Array length: Difference between revisions
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=={{header|MiniZinc}}== |
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<lang MiniZinc> |
<lang MiniZinc> |
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array[int] of |
array[int] of int: arr = [1,2,3]; |
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var int: size = length(arr); |
var int: size = length(arr); |
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Revision as of 21:01, 28 June 2022
You are encouraged to solve this task according to the task description, using any language you may know.
- Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
- Metrics
- Counting
- Word frequency
- Letter frequency
- Jewels and stones
- I before E except after C
- Bioinformatics/base count
- Count occurrences of a substring
- Count how many vowels and consonants occur in a string
- Remove/replace
- XXXX redacted
- Conjugate a Latin verb
- Remove vowels from a string
- String interpolation (included)
- Strip block comments
- Strip comments from a string
- Strip a set of characters from a string
- Strip whitespace from a string -- top and tail
- Strip control codes and extended characters from a string
- Anagrams/Derangements/shuffling
- Word wheel
- ABC problem
- Sattolo cycle
- Knuth shuffle
- Ordered words
- Superpermutation minimisation
- Textonyms (using a phone text pad)
- Anagrams
- Anagrams/Deranged anagrams
- Permutations/Derangements
- Find/Search/Determine
- ABC words
- Odd words
- Word ladder
- Semordnilap
- Word search
- Wordiff (game)
- String matching
- Tea cup rim text
- Alternade words
- Changeable words
- State name puzzle
- String comparison
- Unique characters
- Unique characters in each string
- Extract file extension
- Levenshtein distance
- Palindrome detection
- Common list elements
- Longest common suffix
- Longest common prefix
- Compare a list of strings
- Longest common substring
- Find common directory path
- Words from neighbour ones
- Change e letters to i in words
- Non-continuous subsequences
- Longest common subsequence
- Longest palindromic substrings
- Longest increasing subsequence
- Words containing "the" substring
- Sum of the digits of n is substring of n
- Determine if a string is numeric
- Determine if a string is collapsible
- Determine if a string is squeezable
- Determine if a string has all unique characters
- Determine if a string has all the same characters
- Longest substrings without repeating characters
- Find words which contains all the vowels
- Find words which contains most consonants
- Find words which contains more than 3 vowels
- Find words which first and last three letters are equals
- Find words which odd letters are consonants and even letters are vowels or vice_versa
- Formatting
- Substring
- Rep-string
- Word wrap
- String case
- Align columns
- Literals/String
- Repeat a string
- Brace expansion
- Brace expansion using ranges
- Reverse a string
- Phrase reversals
- Comma quibbling
- Special characters
- String concatenation
- Substring/Top and tail
- Commatizing numbers
- Reverse words in a string
- Suffixation of decimal numbers
- Long literals, with continuations
- Numerical and alphabetical suffixes
- Abbreviations, easy
- Abbreviations, simple
- Abbreviations, automatic
- Song lyrics/poems/Mad Libs/phrases
- Mad Libs
- Magic 8-ball
- 99 Bottles of Beer
- The Name Game (a song)
- The Old lady swallowed a fly
- The Twelve Days of Christmas
- Tokenize
- Text between
- Tokenize a string
- Word break problem
- Tokenize a string with escaping
- Split a character string based on change of character
- Sequences
11l
<lang 11l>print([‘apple’, ‘orange’].len)</lang>
- Output:
2
360 Assembly
Array length is computed at compilation time with the formula : (AEND-A)/L'A <lang 360asm>* Array length 22/02/2017 ARRAYLEN START
USING ARRAYLEN,12 LR 12,15 end of prolog LA 1,(AEND-A)/L'A hbound(a) XDECO 1,PG+13 edit XPRNT PG,L'PG print BR 14 exit
A DC CL6'apple',CL6'orange' array AEND DC 0C PG DC CL25'Array length=' buffer
END ARRAYLEN</lang>
- Output:
Array length= 2
6502 Assembly
Array length is computed at compilation time with the formula: (Array_End-Array). Even though the labels Array and Array_End are both 16-bit values, if their difference fits into 8 bits the assembler will allow you to load it into a register. <lang 6502asm>start: LDA #(Array_End-Array) ;evaluates to 13 RTS
Array: byte "apple",0 byte "orange",0 Array_End:</lang>
68000 Assembly
Array length is computed at compilation time with the formula: (Array_End-Array). Even though the labels Array and Array_End are both 32-bit memory addresses, if their difference is small enough it can fit into a 16-bit or even an 8-bit instruction operand. <lang 68000devpac>start: MOVE.B #(Array_End-Array) ;evaluates to 14 RTS
Array: DC.B "apple",0 even DC.B "orange",0 even Array_End:</lang>
8th
<lang forth> ["apples", "oranges"] a:len . cr </lang>
- Output:
2
AArch64 Assembly
<lang AArch64 Assembly> /* ARM assembly AARCH64 Raspberry PI 3B */ /* program lenAreaString64.s */
/*******************************************/ /* Constantes file */ /*******************************************/ /* for this file see task include a file in language AArch64 assembly*/ .include "../includeConstantesARM64.inc" /*******************************************/ /* Initialized data */ /*******************************************/ .data szMessLenArea: .asciz "The length of area is : @ \n" szCarriageReturn: .asciz "\n"
/* areas strings */ szString1: .asciz "Apples" szString2: .asciz "Oranges" /* pointer items area */ tablesPoi: ptApples: .quad szString1 ptOranges: .quad szString2 ptVoid: .quad 0 /*******************************************/ /* UnInitialized data */ /*******************************************/ .bss sZoneConv: .skip 30 /*******************************************/ /* code section */ /*******************************************/ .text .global main main: // entry of program
ldr x1,qAdrtablesPoi // begin pointer table mov x0,0 // counter
1: // begin loop
ldr x2,[x1,x0,lsl 3] // read string pointer address item x0 (8 bytes by pointer) cmp x2,0 // is null ? cinc x0,x0,ne // no increment counter bne 1b // and loop ldr x1,qAdrsZoneConv // conversion decimal bl conversion10S ldr x0,qAdrszMessLenArea ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at @ character bl affichageMess
100: // standard end of the program
mov x0,0 // return code mov x8,EXIT // request to exit program svc 0 // perform the system call
qAdrtablesPoi: .quad tablesPoi qAdrszMessLenArea: .quad szMessLenArea qAdrsZoneConv: .quad sZoneConv qAdrszCarriageReturn: .quad szCarriageReturn /********************************************************/ /* File Include fonctions */ /********************************************************/ /* for this file see task include a file in language AArch64 assembly */ .include "../includeARM64.inc" </lang>
ABAP
The concept of arrays does not exist in ABAP, instead internal tables are used. Since ABAP Version 7.40 they can be accessed with the common index notation. Note that the index starts at 1 and out of bound access raises an exception. The built-in function "lines" returns the number of records.
<lang ABAP> report z_array_length.
data(internal_table) = value stringtab( ( `apple` ) ( `orange` ) ).
write: internal_table[ 1 ] , internal_table[ 2 ] , lines( internal_table ). </lang>
- Output:
apple orange 2
Ada
<lang Ada>with Ada.Text_IO; use Ada.Text_IO;
procedure Array_Length is
Fruits : constant array (Positive range <>) of access constant String := (new String'("orange"), new String'("apple"));
begin
for Fruit of Fruits loop Ada.Text_IO.Put (Integer'Image (Fruit'Length)); end loop;
Ada.Text_IO.Put_Line (" Array Size : " & Integer'Image (Fruits'Length));
end Array_Length;</lang>
- Output:
6 5 Array Size: 2
ALGOL 68
<lang algol68># UPB returns the upper bound of an array, LWB the lower bound # []STRING fruits = ( "apple", "orange" ); print( ( ( UPB fruits - LWB fruits ) + 1, newline ) ) # prints 2 #</lang>
AntLang
<lang AntLang>array: seq["apple"; "orange"] length[array] /Works as a one liner: length[seq["apple"; "orange"]]</lang>
Apex
<lang apex>System.debug(new String[] { 'apple', 'banana' }.size()); // Prints 2</lang>
APL
<lang apl>⍴'apple' 'orange'</lang> Output:
2
AppleScript
<lang AppleScript> set theList to {"apple", "orange"} count theList -- or length of theList -- or number of items in theList </lang> Strictly speaking, 'items in' can be omitted from the last example, since 'number of' does essentially the same as 'length of'. The additional stage of extracting theList's 'items' is inefficient.
- Output:
2
No context or goal is provided for this task – sometimes for example, we may simply want to take the last member of an array, and counting the length to derive an index might well not be the best route.
More generally, we may learn more about AppleScript by defining length() ourselves. There are two basic functional approaches to doing that – we can write a simple recursive definition, or, if we have a higher order fold/reduce function (see Catamorphism) we can derive length() as:
fold (λx n -> 1 + n) 0
<lang AppleScript>on run
set xs to ["alpha", "beta", "gamma", "delta", "epsilon", ¬ "zeta", "eta", "theta", "iota", "kappa", "lambda", "mu"] {_length(xs), fold(xs, succ, 0), item 12 of xs, item -1 of xs} --> {12, 12, "mu", "mu"}
end run
-- TWO FUNCTIONAL DEFINITIONS OF LENGTH
-- 1. Recursive definition
on _length(xs)
if xs is [] then 0 else 1 + _length(rest of xs) end if
end _length
-- 2. fold (λx n -> 1 + n) 0
on succ(x)
1 + x
end succ
--[a] - > (a - > b) - > b - > [b] on fold(xs, f, startValue)
script mf property lambda : f end script set v to startValue repeat with x in xs set v to mf's lambda(v, x) end repeat
end fold </lang>
- Output:
{12, 12, "mu", "mu"}
ARM Assembly
<lang ARM Assembly> /* ARM assembly Raspberry PI */ /* program lenAreaString.s */
/* Constantes */ .equ STDOUT, 1 @ Linux output console .equ EXIT, 1 @ Linux syscall .equ WRITE, 4 @ Linux syscall /* Initialized data */ .data szMessLenArea: .ascii "The length of area is : " sZoneconv: .fill 12,1,' ' szCarriageReturn: .asciz "\n"
/* areas strings */ szString1: .asciz "Apples" szString2: .asciz "Oranges" /* pointer items area */ tablesPoi: ptApples: .int szString1 ptOranges: .int szString2 ptVoid: .int 0
/* UnInitialized data */ .bss
/* code section */ .text .global main main: /* entry of program */
push {fp,lr} /* saves 2 registers */
ldr r1,iAdrtablesPoi @ begin pointer table mov r0,#0 @ counter
1: @ begin loop
ldr r2,[r1,r0,lsl #2] @ read string pointer address item r0 (4 bytes by pointer) cmp r2,#0 @ is null ? addne r0,#1 @ no increment counter bne 1b @ and loop ldr r1,iAdrsZoneconv @ conversion decimal bl conversion10S ldr r0,iAdrszMessLenArea bl affichageMess
2:
100: /* standard end of the program */
mov r0, #0 @ return code pop {fp,lr} @restaur 2 registers mov r7, #EXIT @ request to exit program swi 0 @ perform the system call
iAdrtablesPoi: .int tablesPoi iAdrszMessLenArea: .int szMessLenArea iAdrsZoneconv: .int sZoneconv iAdrszCarriageReturn: .int szCarriageReturn /******************************************************************/ /* display text with size calculation */ /******************************************************************/ /* r0 contains the address of the message */ affichageMess:
push {fp,lr} /* save registres */ push {r0,r1,r2,r7} /* save others registers */ mov r2,#0 /* counter length */
1: /* loop length calculation */
ldrb r1,[r0,r2] /* read octet start position + index */ cmp r1,#0 /* if 0 its over */ addne r2,r2,#1 /* else add 1 in the length */ bne 1b /* and loop */ /* so here r2 contains the length of the message */ mov r1,r0 /* address message in r1 */ mov r0,#STDOUT /* code to write to the standard output Linux */ mov r7, #WRITE /* code call system "write" */ swi #0 /* call systeme */ pop {r0,r1,r2,r7} /* restaur others registers */ pop {fp,lr} /* restaur des 2 registres */ bx lr /* return */
/***************************************************/ /* conversion register signed décimal */ /***************************************************/ /* r0 contient le registre */ /* r1 contient l adresse de la zone de conversion */ conversion10S:
push {r0-r5,lr} /* save des registres */ mov r2,r1 /* debut zone stockage */ mov r5,#'+' /* par defaut le signe est + */ cmp r0,#0 /* nombre négatif ? */ movlt r5,#'-' /* oui le signe est - */ mvnlt r0,r0 /* et inversion en valeur positive */ addlt r0,#1 mov r4,#10 /* longueur de la zone */
1: /* debut de boucle de conversion */
bl divisionpar10 /* division */ add r1,#48 /* ajout de 48 au reste pour conversion ascii */ strb r1,[r2,r4] /* stockage du byte en début de zone r5 + la position r4 */ sub r4,r4,#1 /* position précedente */ cmp r0,#0 bne 1b /* boucle si quotient different de zéro */ strb r5,[r2,r4] /* stockage du signe à la position courante */ subs r4,r4,#1 /* position précedente */ blt 100f /* si r4 < 0 fin */ /* sinon il faut completer le debut de la zone avec des blancs */ mov r3,#' ' /* caractere espace */
2:
strb r3,[r2,r4] /* stockage du byte */ subs r4,r4,#1 /* position précedente */ bge 2b /* boucle si r4 plus grand ou egal a zero */
100: /* fin standard de la fonction */
pop {r0-r5,lr} /*restaur desregistres */ bx lr
/***************************************************/ /* division par 10 signé */ /* Thanks to http://thinkingeek.com/arm-assembler-raspberry-pi/* /* and http://www.hackersdelight.org/ */ /***************************************************/ /* r0 contient le dividende */ /* r0 retourne le quotient */ /* r1 retourne le reste */ divisionpar10:
/* r0 contains the argument to be divided by 10 */ push {r2-r4} /* save registers */ mov r4,r0 ldr r3, .Ls_magic_number_10 /* r1 <- magic_number */ smull r1, r2, r3, r0 /* r1 <- Lower32Bits(r1*r0). r2 <- Upper32Bits(r1*r0) */ mov r2, r2, ASR #2 /* r2 <- r2 >> 2 */ mov r1, r0, LSR #31 /* r1 <- r0 >> 31 */ add r0, r2, r1 /* r0 <- r2 + r1 */ add r2,r0,r0, lsl #2 /* r2 <- r0 * 5 */ sub r1,r4,r2, lsl #1 /* r1 <- r4 - (r2 * 2) = r4 - (r0 * 10) */ pop {r2-r4} bx lr /* leave function */ bx lr /* leave function */
.Ls_magic_number_10: .word 0x66666667
</lang>
Arturo
<lang rebol>fruit: ["apple" "orange"]
print ["array length =" size fruit]</lang>
- Output:
array length = 2
ATS
<lang ATS>
- include
"share/atspre_staload.hats"
- include
"share/atspre_staload_libats_ML.hats"
val A0 = array0_tuple<string> ( "apple", "orange" ) val () = println!("length(A0) = ", length(A0))
implement main0((*void*)) = ((*void*)) </lang>
AutoHotkey
<lang AutoHotkey>MsgBox % ["apple","orange"].MaxIndex()</lang>
- Output:
2
AutoIt
<lang AutoIt>Opt('MustDeclareVars',1) ; 1 = Variables must be pre-declared.
Local $aArray[2] = ["Apple", "Orange"] Local $Max = UBound($aArray) ConsoleWrite("Elements in array: " & $Max & @CRLF)
For $i = 0 To $Max - 1 ConsoleWrite("aArray[" & $i & "] = '" & $aArray[$i] & "'" & @CRLF) Next </lang>
- Output:
Elements in array: 2 aArray[0] = 'Apple' aArray[1] = 'Orange'
Avail
Using Avail's tuples and the `|_|` method:
<lang Avail>|<"Apple", "Orange">|</lang>
AWK
The main use of the length()-function is to determine the length of a string.
When used on an array, it returns the number of elements.
Another method to count the elements of the array is by using a variant of for().
<lang awk># usage: awk -f arraylen.awk
function countElements(array) {
for( e in array ) {c++} return c
}
BEGIN {
array[1] = "apple" array[2] = "orange"
print "Array length :", length(array), countElements(array) print "String length:", array[1], length(array[1])
}</lang>
- Output:
Array length : 2 2 String length: apple 5
BaCon
BaCon knows three types of arrays, the UBOUND function can query all. <lang bacon>' Static arrays
DECLARE fruit$[] = { "apple", "orange" } PRINT UBOUND(fruit$)
' Dynamic arrays
DECLARE vegetable$ ARRAY 2 vegetable$[0] = "cabbage" vegetable$[1] = "spinach" PRINT UBOUND(vegetable$)
' Associative arrays
DECLARE meat$ ASSOC STRING meat$("first") = "chicken" meat$("second") = "pork" PRINT UBOUND(meat$)</lang>
Bash
<lang bash> fruit=("apple" "orange" "lemon") echo "${#fruit[@]}"</lang>
BASIC
<lang basic>DIM X$(1 TO 2) X$(1) = "apple" X$(2) = "orange" PRINT UBOUND(X$) - LBOUND(X$) + 1</lang>
Applesoft BASIC
<lang basic>10 DIM A$(2) 20 A$(1) = "ORANGE" 30 A$(2) = "APPLE" 40 N$ = "A$": GOSUB 70: PRINT L$
60 PRINT 61 DIM A%(19,63,0),A3(4,5) 62 N$ = "A%": GOSUB 70: PRINT L$ 63 N$ = "A3": GOSUB 70: PRINT L$ 64 N$ = "COMMODORE" 65 GOSUB 70: PRINT L$: END
70 L$ = "":N0 = 0:N1 = 0 71 N0$ = LEFT$ (N$,1) 72 N1$ = MID$ (N$,2,2) 73 N1 = RIGHT$ (N$,1) = "$" 74 N0 = RIGHT$ (N$,1) = "%" 75 IF N0 THEN N1 = 1 76 I = LEN (N1$) - N1 77 N1$ = MID$ (N1$,1,I) 78 A = ASC (N1$ + CHR$ (0)) 79 N1 = 128 * N1 + A 80 N0 = 128 * N0 + ASC (N0$) 90 DEF FN P(A) = PEEK (A) + PEEK (A + 1) * 256 100 I = FN P(109):A = FN P(107) 110 FOR A = A TO I STEP 0 128 IF PEEK (A) < > N0 OR PEEK (A + 1) < > N1 THEN A = A + FN P(A + 2): NEXT A: PRINT "ARRAY "N$" NOT FOUND": STOP 130 N0 = A + 4 140 N1 = N0 + FN P(N0) * 2 150 N0 = N0 + 2 160 FOR I = N1 TO N0 STEP - 2 170 L$ = L$ + STR$ ( FN P(I)) 180 L$ = L$ + " ": NEXT I 190 RETURN</lang>
BASIC256
<lang BASIC256> fruta$ = {"apple", "orange", "pear"}
print length(fruta$) print fruta$[?] print fruta$[1] end </lang>
3 3 orange
Commodore BASIC
Commodore BASIC has no way within the language to query an array for its length, but you can dive into the implementation to get that information. On a C-64 in particular, this works:
<lang basic>10 DIM A$(1):REM 1=LAST -> ROOM FOR 2 20 A$(0) = "ORANGE" 30 A$(1) = "APPLE" 40 AT=0:N$="":T=0:L=0:REM DECLARE ALL VARS BEFORE PEEKING 50 AT=PEEK(47)+256*PEEK(48):REM START OF ARRAYS IN MEMORY 60 N$=CHR$(PEEK(AT)AND127)+CHR$(PEEK(AT+1)AND127):REM NAME 70 T=(PEEK(AT) AND 128)*2+(PEEK(AT+1)AND128):REM TYPE 80 IF T=384 THEN N$=N$+"%": REM INTEGER 90 IF T=128 THEN N$=N$+"$": REM STRING 100 L=PEEK(AT+6): REM FIRST INDEX SIZE 110 PRINT N$" HAS"L"ELEMENTS."</lang>
- Output:
A$ HAS 2 ELEMENTS.
True BASIC
<lang qbasic> DIM fruta$(2) READ fruta$(1), fruta$(2) DATA "apple", "orange"
LET tamano = UBound(fruta$) - LBound(fruta$) + 1
PRINT "La longitud del array fruta$ es" ; tamano END </lang>
- Output:
La longitud del array fruta$ es 2
True BASIC's arrays are not fixed in length and, although True BASIC is a compiled-language, the number of elements can be changed during runtime using such functions as the MAT REDIM (matrix re-dimension) function. Although the starting index of 1 is in implicit, it can be changed by setting the lower and upper bounds (eg. fruit(0 to 3)) when declaring the array. Also, the example below uses the MAT READ function to read in the data elements into the array without having to explicitly list each variable-array index. The example also uses the SIZE function vs the bounds method to determine the length of the array. Finally, in this example the SIZE function was not assigned to a separate variable and instead is used within the PRINT function itself.
<lang qbasic> DIM fruit$(2) MAT READ fruit$ DATA "apple", "orange"
PRINT "The length of the array 'fruit$' is "; SIZE(fruit$) END </lang>
- Output:
The length of the array 'fruit$' is 2
Batch File
While batch files don't support arrays in the traditional sense, sets of variables forming somewhat of a pseudo-array are extremely useful. They are usually in the form of %name{number}%
. The below code gives an example of how to create an array from a list stored in a variable, and how to acquire the amount of entries in the array.
<lang dos> @echo off
- _main
setlocal enabledelayedexpansion
- This block of code is putting a list delimitered by spaces into an pseudo-array
- In practice, this could be its own function _createArray however for the demonstration, it is built in
set colour_list=red yellow blue orange green set array_entry=0 for %%i in (%colour_list%) do (
set /a array_entry+=1 set colours[!array_entry!]=%%i
)
call:_arrayLength colours echo _arrayLength returned %errorlevel% pause>nul exit /b
- _arrayLength returns the length of the array parsed to it in the errorcode
- _arrayLength
setlocal enabledelayedexpansion
- loop
set /a arrayentry=%arraylength%+1 if "!%1[%arrayentry%]!"=="" exit /b %arraylength% set /a arraylength+=1 goto loop </lang>
- Input:
red yellow blue orange green
- Output:
_arrayLength returned 5
BBC BASIC
<lang bbcbasic> DIM array$(1)
array$() = "apple", "orange" PRINT "Number of elements in array = "; DIM(array$(), 1) + 1 PRINT "Number of bytes in all elements combined = "; SUMLEN(array$()) END</lang>
- Output:
Number of elements in array = 2 Number of bytes in all elements combined = 11
Brat
<lang brat> p ["apple", "orange"].length </lang>
BQN
≠
gives the length of an array in BQN.
<lang bqn>≠ 1‿"a"‿+</lang>
<lang bqn>3</lang>
Try It!
C
A commonly used solution
C features two kinds of arrays: static (compile-time, fixed size) and dynamic (allocated at runtime).
The length of a dynamic array cannot be acquired from the array itself - its length must be stored elsewhere.
For static arrays:
<lang c>
- include <stdio.h>
int main() {
const char *fruit[2] = { "apples", "oranges" };
// Acquire the length of the array by dividing the size of all elements (found // with sizeof(fruit)) by the size of the first element.
// Note that since the array elements are pointers to null-terminated character // arrays, the size of the first element is actually the size of the pointer // type - not the length of the string.
// This size, regardless of the type being pointed to, is 8 bytes, 4 bytes, or // 2 bytes on 64-bit, 32-bit, or 16-bit platforms respectively. int length = sizeof(fruit) / sizeof(fruit[0]);
printf("%d\n", length);
return 0;
} </lang>
A C pre-processor macro may be created for ease of use:
<lang c>
- define ARRAY_LENGTH(A) (sizeof(A) / sizeof(A[0]))
</lang>
Note that these arrays become pointers when passed as a parameter to a function. Thus, the length of an array parameter may not be required directly - a dedicated length parameter would be required.
Safe solution
The C language uses arrays of a declared size (including variable length arrays, i.e. VLA) and dynamically allocated memory blocks. While they are mostly the same, it is important that the sizeof operator, which returns a number of bytes, behaves quite differently for arrays and for memory pointers.
The problem is that arrays are passed to functions (procedures) via pointers. Even if we define a global variable as an array, after using it as a function argument the appropriate parameter will "forget" what size the array is.
Therefore, an object-oriented technique is used in the solution below. (This is possible even with standard C, i.e. C without ++.) Block of memory in which is stored the array is wrapped in structure and thus the size of the array can be easily stored. It is very convenient. Having defined such "classes" as StringArray, their use is easy and hassle-free. Nevertheless, the C language is not designed for OOP, and therefore C ++ is simply better for these kinds of applications.
Solution
<lang C>#define _CRT_SECURE_NO_WARNINGS // turn off panic warnings
- define _CRT_NONSTDC_NO_WARNINGS // enable old-gold POSIX names in MSVS
- include <stdarg.h>
- include <stdio.h>
- include <stdlib.h>
- include <string.h>
- include <assert.h>
struct StringArray
{
size_t sizeOfArray; size_t numberOfElements; char** elements;
}; typedef struct StringArray* StringArray;
StringArray StringArray_new(size_t size) {
StringArray this = calloc(1, sizeof(struct StringArray)); if (this) { this->elements = calloc(size, sizeof(int)); if (this->elements) this->sizeOfArray = size; else { free(this); this = NULL; } } return this;
}
void StringArray_delete(StringArray* ptr_to_this) {
assert(ptr_to_this != NULL); StringArray this = (*ptr_to_this); if (this) { for (size_t i = 0; i < this->sizeOfArray; i++) free(this->elements[i]); free(this->elements); free(this); this = NULL; }
}
void StringArray_add(StringArray this, ...) {
char* s; va_list args; va_start(args, this); while (this->numberOfElements < this->sizeOfArray && (s = va_arg(args, char*))) this->elements[this->numberOfElements++] = strdup(s); va_end(args);
}
int main(int argc, char* argv[])
{
StringArray a = StringArray_new(10); StringArray_add(a, "apple", "orange", NULL);
printf( "There are %d elements in an array with a capacity of %d elements:\n\n", a->numberOfElements, a->sizeOfArray);
for (size_t i = 0; i < a->numberOfElements; i++) printf(" the element %d is the string \"%s\"\n", i, a->elements[i]);
StringArray_delete(&a);
return EXIT_SUCCESS;
}</lang>
- Output:
There are 2 elements in an array with a capacity of 10 elements: the element 0 is the string "apple" the element 1 is the string "orange"
An example why sizeof(A)/sizeof(E) may be a bad idea in C
<lang C>#define _CRT_SECURE_NO_WARNINGS // turn off panic warnings
- define _CRT_NONSTDC_NO_WARNINGS // enable old-gold POSIX names in MSVS
- include <stdio.h>
- include <stdlib.h>
- include <time.h>
- define N 10
// Fixed size global arrays
static const int scGlobal[N]; const int cGlobal[N]; static int sGlobal[N]; int Global[N];
- define TEST(A, N) \
do { \ puts(""); \ printf("directly called: sizeof(%8s) = %2d, length = %2d, %s\n",\ #A, \ sizeof(A), \ sizeof(A) / sizeof(int), \ sizeof(A) / sizeof(int) == N ? "pass" : "fail"); \ \ test1(#A, A, N); \ test2(#A, A, N); \ test3(#A, A, N); \
} while (0);
void test1(char* name, int* A, int n) {
printf("as parameter int* A: sizeof(%8s) = %2d, length = %2d, %s\n", name, sizeof(A), sizeof(A) / sizeof(int), sizeof(A) / sizeof(int) == n ? "pass" : "fail");
}
void test2(char* name, int A[], int n) {
printf("as parameter int A[]: sizeof(%8s) = %2d, length = %2d, %s\n", name, sizeof(A), sizeof(A) / sizeof(int), sizeof(A) / sizeof(int) == n ? "pass" : "fail");
}
void test3(char* name, int A[10], int n) {
printf("as parameter int A[10]: sizeof(%8s) = %2d, length = %2d, %s\n", name, sizeof(A), sizeof(A) / sizeof(int), sizeof(A) / sizeof(int) == n ? "pass" : "fail");
}
int main(int argc, char argv[])
{
// Fixed size local arrays (defined inside curly braces block)
static const int scLocal[N]; const int cLocal[N]; static int sLocal[N]; auto int aLocal[N]; int Local[N];
// Fixed size VLA arrays can/should be used instead dynamically alocated // blocks. VLA has not implemented in Microsoft Visual Studio C.
srand(time(NULL)); int n = N + rand() % 2; // the value of n is unknow in the compile time?
- ifndef _MSC_VER
int vlaLocal[n];
- endif
// Memory blocks as ersatz arrays. This is not all possible ways to allocate // memory. There are other functions, like LocalAlloc, HeapAlloc, sbreak... // Don't use alloca in any serious program - this function is really bad // choice - it can corrupt the program stack and generate a stack overflow.
int* mBlock = (int*)malloc(n * sizeof(int)); int* cBlock = (int*)calloc(n, sizeof(int)); int* aBlock = (int*)_alloca(n * sizeof(int)); // don't use in your programs!
TEST(scGlobal, N); TEST(cGlobal, N); TEST(sGlobal, N); TEST(Global, N);
TEST(scLocal, N); TEST(cLocal, N); TEST(sLocal, N); TEST(aLocal, N); TEST(Local, N);
- ifndef _MSC_VER
TEST(vlaLocal, n);
- endif
TEST(mBlock, N); TEST(cBlock, N); TEST(aBlock, N);
free(mBlock, N); free(cBlock, N); // free must not be called on aBlock
return 0;
}</lang>
As we can see the sizeof(ArrayType)/sizeof(ElementType) approach mostly fail.
- Output:
directly called: sizeof(scGlobal) = 40, length = 10, pass as parameter int* A: sizeof(scGlobal) = 4, length = 1, fail as parameter int A[]: sizeof(scGlobal) = 4, length = 1, fail as parameter int A[10]: sizeof(scGlobal) = 4, length = 1, fail directly called: sizeof( cGlobal) = 40, length = 10, pass as parameter int* A: sizeof( cGlobal) = 4, length = 1, fail as parameter int A[]: sizeof( cGlobal) = 4, length = 1, fail as parameter int A[10]: sizeof( cGlobal) = 4, length = 1, fail directly called: sizeof( sGlobal) = 40, length = 10, pass as parameter int* A: sizeof( sGlobal) = 4, length = 1, fail as parameter int A[]: sizeof( sGlobal) = 4, length = 1, fail as parameter int A[10]: sizeof( sGlobal) = 4, length = 1, fail directly called: sizeof( Global) = 40, length = 10, pass as parameter int* A: sizeof( Global) = 4, length = 1, fail as parameter int A[]: sizeof( Global) = 4, length = 1, fail as parameter int A[10]: sizeof( Global) = 4, length = 1, fail directly called: sizeof( scLocal) = 40, length = 10, pass as parameter int* A: sizeof( scLocal) = 4, length = 1, fail as parameter int A[]: sizeof( scLocal) = 4, length = 1, fail as parameter int A[10]: sizeof( scLocal) = 4, length = 1, fail directly called: sizeof( cLocal) = 40, length = 10, pass as parameter int* A: sizeof( cLocal) = 4, length = 1, fail as parameter int A[]: sizeof( cLocal) = 4, length = 1, fail as parameter int A[10]: sizeof( cLocal) = 4, length = 1, fail directly called: sizeof( sLocal) = 40, length = 10, pass as parameter int* A: sizeof( sLocal) = 4, length = 1, fail as parameter int A[]: sizeof( sLocal) = 4, length = 1, fail as parameter int A[10]: sizeof( sLocal) = 4, length = 1, fail directly called: sizeof( aLocal) = 40, length = 10, pass as parameter int* A: sizeof( aLocal) = 4, length = 1, fail as parameter int A[]: sizeof( aLocal) = 4, length = 1, fail as parameter int A[10]: sizeof( aLocal) = 4, length = 1, fail directly called: sizeof( Local) = 40, length = 10, pass as parameter int* A: sizeof( Local) = 4, length = 1, fail as parameter int A[]: sizeof( Local) = 4, length = 1, fail as parameter int A[10]: sizeof( Local) = 4, length = 1, fail directly called: sizeof( mBlock) = 4, length = 1, fail as parameter int* A: sizeof( mBlock) = 4, length = 1, fail as parameter int A[]: sizeof( mBlock) = 4, length = 1, fail as parameter int A[10]: sizeof( mBlock) = 4, length = 1, fail directly called: sizeof( cBlock) = 4, length = 1, fail as parameter int* A: sizeof( cBlock) = 4, length = 1, fail as parameter int A[]: sizeof( cBlock) = 4, length = 1, fail as parameter int A[10]: sizeof( cBlock) = 4, length = 1, fail directly called: sizeof( aBlock) = 4, length = 1, fail as parameter int* A: sizeof( aBlock) = 4, length = 1, fail as parameter int A[]: sizeof( aBlock) = 4, length = 1, fail as parameter int A[10]: sizeof( aBlock) = 4, length = 1, fail
C#
<lang csharp> using System;
class Program {
public static void Main() { var fruit = new[] { "apple", "orange" }; Console.WriteLine(fruit.Length); }
} </lang>
Note that any of the following array declarations could be used:
<lang csharp> var fruit = new[] { "apple", "orange" }; var fruit = new string[] { "apple", "orange" }; string[] fruit = new[] { "apple", "orange" }; string[] fruit = new string[] { "apple", "orange" }; string[] fruit = { "apple", "orange" }; </lang>
A shorter variant could also have been used:
<lang csharp> using static System.Console;
class Program {
public static void Main() { WriteLine(new[] { "apples", "oranges" }.Length); }
} </lang>
C++
C++ follows the same rules as C regarding static and dynamic arrays.
However, C++ has an additional std::array
type (amongst other collections) in its standard library:
<lang cpp>#include <array>
- include <iostream>
- include <string>
int main() {
std::array<std::string, 2> fruit { "apples", "oranges" }; std::cout << fruit.size(); return 0;
}</lang>
Note that char*
or const char*
could have been used instead of std::string
.
In addition to the std::array
type, the C++ standard library also provides dynamically-sized containers to hold arbitrary objects.
These all support similar interfaces, though their implementations have different performance characteristics.
<lang cpp> std::vector<std::string> fruitV({ "apples", "oranges" });
std::list<std::string> fruitL({ "apples", "oranges" }); std::deque<std::string> fruitD({ "apples", "oranges" }); std::cout << fruitV.size() << fruitL.size() << fruitD.size() << std::endl;</lang>
Of these, vector is probably the most widely used.
Ceylon
<lang ceylon>shared void run() { value array = ["apple", "orange"]; print(array.size); }</lang>
Clipper/XBase++
<lang Clipper/XBase++>/*
* nizchka: March - 2016 * This is a Clipper/XBase++ of RosettaCode Array_Length */
PROCEDURE MAIN()
LOCAL FRUIT := { "apples","oranges" }
? LEN(FRUIT)
RETURN </lang>
Outputs:
2
nizchka 23:27, 16 March 2016 (UTC)
Clojure
<lang clojure>; using count: (count ["apple" "orange"])
- OR alength if using Java arrays
(alength (into-array ["apple" "orange"]))</lang>
COBOL
Arrays in COBOL are usually referred to as tables. Tables can have fixed or variable (with known maximum) allocations, using a syntax of OCCURS DEPENDING ON. The value of the ODO identifier is the number of active elements in the table.
<lang COBOL> identification division.
program-id. array-length.
environment division. configuration section. repository. function all intrinsic.
data division. working-storage section. 01 table-one. 05 str-field pic x(7) occurs 0 to 5 depending on t1.
77 t1 pic 99.
procedure division. array-length-main. perform initialize-table perform display-table-info goback.
initialize-table. move 1 to t1 move "apples" to str-field(t1)
add 1 to t1 move "oranges" to str-field(t1).
*> add an extra element and then retract table size add 1 to t1 move "bananas" to str-field(t1). subtract 1 from t1 .
display-table-info. display "Elements: " t1 ", using " length(table-one) " bytes" display table-one .
end program array-length.</lang>
- Output:
$ cobc -xjd array-length.cob Elements: 02, using 000000014 bytes apples oranges
ColdFusion
<lang coldfusion> <cfset testArray = ["apple","orange"]> <cfoutput>Array Length = #ArrayLen(testArray)#</cfoutput> </lang>
Outputs:
Array Length = 2
Mike Knapp 15:57, 26 May 2016 (UTC)
Common Lisp
<lang Lisp> (print (length #("apple" "orange"))) </lang>
Alternate solution
I use Allegro CL 10.1
<lang lisp>
- Project
- Array length
(setf my-array (make-array '(2))) (setf (aref my-array 0) "apple") (setf (aref my-array 1) "orange") (format t "~a" "length of my-array: ") (length my-array) (terpri) </lang> Output:
length of my-array: 2
Component Pascal
<lang oberon2> MODULE AryLen; IMPORT StdLog;
TYPE String = POINTER TO ARRAY OF CHAR; VAR a: ARRAY 16 OF String;
PROCEDURE NewString(s: ARRAY OF CHAR): String; VAR str: String; BEGIN NEW(str,LEN(s$) + 1);str^ := s$; RETURN str END NewString;
PROCEDURE Length(a: ARRAY OF String): INTEGER; VAR i: INTEGER; BEGIN i := 0; WHILE a[i] # NIL DO INC(i) END; RETURN i END Length;
PROCEDURE Do*; BEGIN a[0] := NewString("Apple"); a[1] := NewString("Orange"); StdLog.String("Length:> ");StdLog.Int(Length(a));StdLog.Ln END Do;
END AryLen. </lang> Execute: ^Q AryLen.Do
- Output:
Length:> 2
Crystal
<lang ruby> puts ["apple", "orange"].size </lang>
- Output:
2
D
<lang d> import std.stdio;
int main() {
auto fruit = ["apple", "orange"]; fruit.length.writeln; return 0;
} </lang>
Or a somewhat shorter... <lang d> import std.stdio;
void main() {
["apple", "orange"].length.writeln;
} </lang>
Dart
<lang dart> arrLength(arr) {
return arr.length;
}
main() {
var fruits = ['apple', 'orange']; print(arrLength(fruits));
}
</lang>
DataWeave
<lang DataWeave>var arr = ["apple", "orange"] sizeOf(arr) </lang>
Delphi
<lang delphi>
showmessage( length(['a','b','c']).ToString );
</lang>
Dragon
<lang dragon>select "std"
a = ["apple","orange"] b = length(a)
show b </lang>
Dyalect
<lang dyalect>var xs = ["apple", "orange"] print(xs.Length())</lang>
EasyLang
<lang>fruit$[] = [ "apples" "oranges" ] print len fruit$[]</lang>
EchoLisp
<lang scheme> (length '("apple" "orange")) ;; list
→ 2
(vector-length #("apple" "orange")) ;; vector
→ 2
</lang>
Ela
<lang ela>length [1..10]</lang>
Elena
ELENA 5.0 : <lang elena>
var array := new string[]{"apple", "orange"}; var length := array.Length;
</lang>
Elixir
<lang elixir>iex(1)> length( ["apple", "orange"] ) # List 2 iex(2)> tuple_size( {"apple", "orange"} ) # Tuple 2</lang>
Elm
<lang elm> import Array import Html
main : Html.Html main =
["apple", "orange"] |> Array.fromList |> Array.length |> Basics.toString |> Html.text
</lang>
Emacs Lisp
<lang Lisp>(length ["apple" "orange"]) => 2</lang>
length
also accepts a list or a string.
Erlang
<lang Erlang> 1> length(["apple", "orange"]). %using a list 2 1> tuple_size({"apple", "orange"}). %using a tuple 2 </lang>
Euphoria
<lang Euphoria> sequence s = {"apple","orange",2.95} -- Euphoria doesn't care what you put in a sequence
? length(s)
3 -- three objects
? length(s[1])
5 -- apple has 5 characters
? length(s[1][$])
1 -- 'e' is an atomic value
? length(s[$])
1 -- 2.95 is an atomic value
</lang>
F#
<lang fsharp>[|1;2;3|].Length |> printfn "%i"</lang> Or: <lang fsharp>[|1;2;3|] |> Array.length |> printfn "%i"</lang>
Factor
<lang factor> { "apple" "orange" } length </lang>
Forth
The philosophy of Chuck Moore, the creator of Forth was that he did not want to write code for something he may never use. His solution was to distill his language into a large set of very simple routines that control the hardware directly. This demonstration must build "arrays" from scratch. In Forth, like in Assembler, you can do this any way you want. This demonstration adds new words to Forth that make a syntax to create simple variable length string arrays. Each string is a counted string with no trailing zero.
The code is commented to explain what is going on for those unfamiliar with Forth.
<lang>: STRING, ( caddr len -- ) \ Allocate space & compile string into memory
HERE OVER CHAR+ ALLOT PLACE ;
- " ( -- ) [CHAR] " PARSE STRING, ; \ Parse input to " and compile to memory
\ Array delimiter words
- { ALIGN 0 C, ; \ Compile 0 byte start/end of array
- } ALIGN 0 C, ;
\ String array words
- {NEXT} ( str -- next_str) \ Iterate to next string
COUNT + ;
- {NTH} ( n array_addr -- str) \ Returns address of the Nth item in the array
SWAP 0 DO {NEXT} LOOP ;
- {LEN} ( array_addr -- n) \ count strings in the array
0 >R \ Counter on Rstack {NEXT} BEGIN DUP C@ \ Fetch length byte WHILE \ While true R> 1+ >R \ Inc. counter {NEXT} REPEAT DROP R> ; \ return counter to data stack </lang>
Test code at Forth console <lang forth>CREATE Q { " Apples" " Oranges" } q {len} . 2 ok</lang>
Fortran
Early fortrans offered no protocol for ascertaining the length (or dimensionality) of arrays, though the compiler has this information. Thus a statement such as PRINT A
would print all the elements of a variable A
according to its definition. A subprogram that received a parameter would have no access to these details, so its parameter might be declared as A(12345)
simply to signify that it was an array (rather than an ordinary variable) and the programmer would rely on other data to know the upper bound to employ, for instance via an additional parameter. Any mistakes would cause crashes! On the other hand, with heavy computational tasks, it was common to take advantage of the opportunities. Thus, a subprogram might regard its array parameter as one-dimensional even though the actual parameter was not. Carefully-programmed routines might thusly process a sequence of elements via 1-D indexing, far faster than the 2-D or higher order indexing of the original. Success at this game required understanding how array elements were arranged in multidimensional arrays.
Later fortrans allowed A(*)
to signify an array parameter of unstated upper bound, but there was still a problem with higher dimensions. All but the last dimension has to be stated correctly if a multi-dimensional array parameter is to be indexed correctly - Fortran stores array elements in column-major order.
With Fortran 90, a new protocol was introduced, whereby the parameter might be declared as A(:)
signifying an array of one dimension, of bounds unstated. A 2-D array would have A(:,:)
and so on. Further, arrays could have arbitrary lower bounds as well, as in A(-7:12)
but if no colon appeared for a dimension, the lower bound would be assumed to be one so A(2)
means an array of two elements, as before. And as before, in a subprogram a bound could be explicitly stated, perhaps via an explicit parameter such as N
, but now with the :
scheme, the compiler is passing secret additional parameters to the subprogram giving the bounds of the array, and these can be accessed via the library functions LBOUND and UBOUND. For multi-dimensional arrays there are multiple bounds, and an invocation might be UBOUND(A,DIM = 2)
but in the example only a one-dimensional array is involved. These facilities are available only if the new MODULE protocol is employed.
The task is in terms of an array holding the texts "Apple" and "Orange", so a CHARACTER*6 element size will do; the subprogram receives yet another secret parameter specifying the size of CHARACTER parameters. This size can be accessed via the LEN function, and, since in principle the index span is arbitrary, no constant index is sure to be a valid index of some single element: thus the LBOUND function is used to finger one that is.
For a simple example, the WRITE(6,*) suffices: write to standard output (the 6), in free-format (the *).
<lang Fortran>
MODULE EXAMPLE CONTAINS SUBROUTINE ABOUND(A) CHARACTER*(*) A(:) !One dimensional array, unspecified bounds. WRITE (6,*) "Lower bound",LBOUND(A),", Upper bound",UBOUND(A) WRITE (6,*) "Element size",LEN(A(LBOUND(A))) WRITE (6,*) A END SUBROUTINE ABOUND END MODULE EXAMPLE
PROGRAM SHOWBOUNDS USE EXAMPLE CHARACTER*6 ARRAY(-1:1) ARRAY(-1) = "Apple" ARRAY(0) = "Orange" ARRAY(1) = "" CALL ABOUND(ARRAY) WRITE (6,*) "But, when it is at home..." WRITE (6,*) "L. bound",LBOUND(ARRAY),", U. bound",UBOUND(ARRAY) END
</lang>
Output:
Lower bound 1 , Upper bound 3 Element size 6 Apple Orange But, when it is at home... L. bound -1 , U. bound 1
Notice that the subprogram sees the array as an old-style array starting with index one! If it is to work with a lower bound other than one, the declaration in the subprogram must state it, perhaps as A(-1:) or as A(START:), etc. The upper bound remains unspecified, and with that declaration, UBOUND returns 1 instead of 3, corresponding to the shift. Thus, UBOUND returns not the actual upper bound of the array parameter (as supplied) but the upper bound relative to the lower bound in use in the subprogram so that UBOUND - LBOUND + 1 does give the number of elements.
If in the subprogram the bounds are fixed (say as A(-1:6)
) then a CALL ABOUND(ARRAY) may provoke a compiler complaint if ARRAY is not a suitable size.
FreeBASIC
<lang freebasic>' FB 1.05.0 Win64
Dim fruit(1) As String = {"apple", "orange"} Dim length As Integer = UBound(fruit) - LBound(fruit) + 1 Print "The length of the fruit array is"; length Print Print "Press any key to quit the program" Sleep</lang>
- Output:
The length of the fruit array is 2
Frink
<lang frink> a = ["apple", "orange"] println[length[a]] </lang>
FurryScript
<lang furryscript>THE_LIST( <apple> <orange> ) COUNT[ 0 SW ~| COUNT_STEP# 0 SW SU ] COUNT_STEP[ DR 1 SU ]
`THE_LIST COUNT# +<></lang>
Futhark
The shape
builtin returns the shape of an array as an array of integers. The length is element 0 of the shape:
<lang Futhark> fun length(as: []int): int = (shape as)[0] </lang>
FutureBasic
NSUInteger count = fn ArrayCount( array ). Example: <lang futurebasic> window 1 print fn ArrayCount( @[@"apple",@"orange",@"cherry",@"grape",@"lemon"] ) HandleEvents </lang>
- Output:
5
Fōrmulæ
Fōrmulæ programs are not textual, visualization/edition of programs is done showing/manipulating structures but not text. Moreover, there can be multiple visual representations of the same program. Even though it is possible to have textual representation —i.e. XML, JSON— they are intended for storage and transfer purposes more than visualization and edition.
Programs in Fōrmulæ are created/edited online in its website, However they run on execution servers. By default remote servers are used, but they are limited in memory and processing power, since they are intended for demonstration and casual use. A local server can be downloaded and installed, it has no limitations (it runs in your own computer). Because of that, example programs can be fully visualized and edite/d, but some of them will not run if they require a moderate or heavy computation/memory resources, and no local server is being used.
In this page you can see the program(s) related to this task and their results.
Gambas
Click this link to run this code <lang gambas>Public Sub Main() Dim siList As Short[] = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]
Print siList.Count
End</lang> Output:
10
Genie
<lang genie>[indent=4] /* Array length, in Genie */ init
arr:array of string = {"apple", "orange"} stdout.printf("%d ", arr.length) print arr[1]</lang>
- Output:
prompt$ valac array_length.gs prompt$ ./array_length 2 orange
Go
<lang Go>package main
import "fmt"
func main() { arr := [...]string{"apple", "orange", "pear"}
fmt.Printf("Length of %v is %v.\n", arr, len(arr)) }</lang>
- Output:
Length of [apple orange pear] is 3.
Groovy
<lang Groovy> def fruits = ['apple','orange'] println fruits.size() </lang>
Harbour
<lang visualfoxpro> LOCAL aFruits := {"apple", "orange"} Qout( Len( aFruits ) ) // --> 2 </lang>
Haskell
<lang Haskell>-- Char -> Int length ["apple", "orange"]</lang>
hexiscript
<lang hexiscript>let a arr 2 let a[0] "apple" let a[1] "orange" println len a</lang>
Hoon
<lang Hoon>|= arr=(list *) (lent arr)</lang>
i
<lang i>main: print(#["apple", "orange"])</lang>
Icon and Unicon
Icon, and therefore Unicon, includes a prefix size operator, star *
. This operator can be applied to just about any data type or data structure.
<lang unicon>write(*["apple", "orange"])</lang>
Idris
<lang Idris>length ["apple", "orange"]</lang>
J
Tally (#
) returns the length of the leading dimension of an array (or 1 if the array has no dimensions). Shape Of ($
) returns the length of each dimension of an array.
<lang j> # 'apple';'orange'
2
$ 'apple';'orange'
2</lang> For the list array example given, the result appears to be the same. The difference is that the result of Tally is a scalar (array of 0 dimensions) whereas the result of Shape Of is a list (1 dimensional array), of length 1 in this case. <lang j> $#'apple';'orange'
$$'apple';'orange'
1</lang> This might be a clearer concept with a few more examples. Here's an array with two dimensions: <lang j> >'apple';'orange' apple orange
$>'apple';'orange'
2 6
#>'apple';'orange'
2</lang> And, here's an array with no dimensions: <lang> 9001 9001
#9001
1
$9001
</lang>
You can count the number of dimensions of an array (the length of the list of lengths) using #$array
:
<lang j>
#$9001
0
#$'apple';'orange'
1
#$>'apple';'orange'
2</lang>
Janet
<lang janet> (def our-array @["apple" "orange"]) (length our-array) </lang>
- Output:
2
Java
<lang java>public class ArrayLength {
public static void main(String[] args) { System.out.println(new String[]{"apple", "orange"}.length); }
}</lang>
JavaScript
<lang javascript>console.log(['apple', 'orange'].length);</lang>
However, determining the length of a list, array, or collection may simply be the wrong thing to do.
If, for example, the actual task (undefined here, unfortunately) requires retrieving the final item, while it is perfectly possible to write last in terms of length
<lang JavaScript>function last(lst) {
return lst[lst.length - 1];
}</lang>
using length has the disadvantage that it leaves last simply undefined for an empty list.
We might do better to drop the narrow focus on length, and instead use a fold (reduce, in JS terms) which can return a default value of some kind.
<lang JavaScript>function last(lst) {
return lst.reduce(function (a, x) { return x; }, null);
}</lang>
Alternatively, rather than scanning the entire list to simply get the final value, it might sometimes be better to test the length:
<lang JavaScript>function last(list, defaultValue) {
return list.length ?list[list.length-1] :defaultValue;
}</lang>
Or use other built-in functions – this, for example, seems fairly clear, and is already 100+ times faster than unoptimised tail recursion in ES5 (testing with a list of 1000 elements):
<lang JavaScript>function last(list, defaultValue) {
return list.slice(-1)[0] || defaultValue;
}</lang>
jq
<lang jq>["apple","orange"] | length</lang> Output: <lang sh>2</lang>
Note that the length filter is polymorphic, so for example the empty string (""), the empty list ([]), and null all have length 0.
Jsish
<lang javascript>/* Array length, in jsish */ var arr = new Array('apple', 'orange'); puts(arr.length); puts(arr[1]);</lang>
- Output:
prompt$ jsish arrayLength.jsi 2 orange
Julia
<lang Julia> a = ["apple","orange"] length(a) </lang>
Klingphix
<lang Klingphix>include ..\Utilitys.tlhy
( "apple" "orange" ) len print
" " input</lang>
- Output:
2
Klong
<lang K>
- ["apple" "orange"]
</lang>
Kotlin
<lang scala>fun main(args: Array<String>) {
println(arrayOf("apple", "orange").size)
}</lang>
Lambdatalk
<lang scheme> {A.length {A.new 1 2 3}} -> 3 </lang>
Latitude
In Latitude, length
and size
are synonymous and will both retrieve the size of a collection.
<lang latitude>println: ["apple", "orange"] length.</lang>
Liberty BASIC
When a one or two dimensional array, A$, with subscript(s) of 10 or less is referenced (either by assigning or reading), the compiler does an implicit DIM A$(10) or DIM A$(10,10). Before referencing an array with any subscript numbered higher than 10, or arrays of three dimensions or more, the programmer must first issue an explicit DIM statement.
There is no function in Liberty Basic to directly read the size of an array. This program uses error trapping loops to, first, determine the number of dimensions of the array. Then, second, again uses error trapping loops to determine the number of elements in each dimension. Finally, it prints the DIM statement that was used to define the array.
I suppose the implicit DIM feature makes it a bit quicker to write short, simple programs. One or two dimension arrays may be resized with REDIM. Three dimension or more arrays can not be resized. All arrays may be cleared with REDIM. Keep in mind that A$(n) and A$(n,m) are the same array. You must refer to it with the correct arguments or get an error.
NOTE -- This program runs only under LB Booster version 3.05 or higher because of arrays with more than two dimensions, passed array names to functions and subroutines as a parameter, and structured error trapping syntax. Get the LBB compiler here: http://lbbooster.com/
<lang lb> FruitList$(0)="apple" 'assign 2 cells of a list array FruitList$(1)="orange" dimension=dimension(FruitList$()) 'first get the dimension of the array if dimension>3 then
print "Sorry, program only written for array dimensions of 3 or less." end
end if call elements FruitList$(), dimension 'next get the size of each dimension end
function dimension(array$())
for dimension=1 to 4 select case dimension case 1 try: x$=array$(0) catch: goto [TryNext] end try exit for case 2 try: x$=array$(0,0) catch: goto [TryNext] end try exit for case 3 try: x$=array$(0,0,0) catch: goto [TryNext] end try exit for case 4 exit for end select [TryNext] next dimension if dimension<4 then print "array dimension = "; dimension ArraySize(0)=dimension
end function
sub elements array$(), dimension
select case dimension case 1 try do x$=array$(a) a+=1 loop catch: elements=a end try ArraySize(1)=elements-1 print "dimension 1 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(1) case 2 try do x$=array$(a,0) a+=1 loop catch: elements=a end try ArraySize(1)=elements-1 print "dimension 1 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(1) elements=0 try do x$=array$(0,b) b+=1 loop catch: elements=b end try ArraySize(2)=elements-1 print "dimension 2 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(2) case 3 try do x$=array$(a,0,0) a+=1 loop catch: elements=a end try ArraySize(1)=elements-1 print "dimension 1 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(1) elements=0 try do x$=array$(0,b,0) b+=1 loop catch: elements=b end try ArraySize(2)=elements-1 print "dimension 2 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(2) elements=0 try do x$=array$(0,0,c) c+=1 loop catch: elements=c end try ArraySize(3)=elements-1 print "dimension 3 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(3) end select 'print the explicit or implied DIMension statement for this array print "DIM array$("; a-1; if b>0 then print ","; b-1; if c>0 then print ","; c-1; print ")"
end sub </lang>
- Output:
array dimension = 1 dimension 1 has 11 elements (cells), numbered 0 to 10 DIM array$(10)
LIL
LIL does not use arrays, but indexed lists. The builtin count command returns the item count in a list. The length command returns the length of the list after string conversion.
<lang tcl># Array length, in LIL set a [list "apple"] append a "orange" print [count $a] print [index $a 1]</lang>
- Output:
prompt$ lil arrayLength.lil 2 orange
Limbo
<lang Limbo>implement Command;
include "sys.m"; sys: Sys;
include "draw.m";
include "sh.m";
init(nil: ref Draw->Context, nil: list of string) { sys = load Sys Sys->PATH;
a := array[] of {"apple", "orange"}; sys->print("length of a: %d\n", len a); }</lang>
Lingo
<lang lingo>fruits = ["apple", "orange"] put fruits.count -- 2</lang>
Little
<lang C>string fruit[] = {"apples", "oranges"}; puts(length(fruit));</lang>
LiveCode
<lang LiveCode>put "apple","orange" into fruit split fruit using comma answer the number of elements of fruit</lang>
Lua
<lang Lua>-- For tables as simple arrays, use the # operator: fruits = {"apple", "orange"} print(#fruits)
-- Note the # symbol does not work for non-integer-indexed tables: fruits = {fruit1 = "apple", fruit2 = "orange"} print(#fruits)
-- For this you can use this short function: function size (tab)
local count = 0 for k, v in pairs(tab) do count = count + 1 end return count
end
print(size(fruits))</lang>
- Output:
2 0 2
M2000 Interpreter
<lang M2000 Interpreter> \\ A is a pointer to array A=("Apple", "Orange") Print Len(A)=2 ' True Print Dimension(A, 0) ' LBound (0 or 1), here 0 Print Dimension(A) ' No of Dimensions 1 Print Dimension(A, 1) ' for 1 dimension array this is also Length=2 \\ A$( ) is an Array (not a pointer to array) Dim Base 1, A$(2) A$(1)="Apple", "Orange" Print Dimension(A$(), 0) ' LBound (0 or 1), here 1 Print Dimension(A$()) ' No of Dimensions 1 Print Dimension(A$(), 1) ' for 1 dimension array this is also Length=2 Link A to B$() ' B$() is a reference to A Print B$(0)=A$(1) Print B$(1)=A$(2) Dim C$() \\ C$() get a copy of B$() C$()=B$() Print C$() ' prints Apple Orange \\ An array can link to a new name as reference, and can change major type \\ here A$() get A() so we can read/store numbers and read/store strings in same array \\ using two names Link A$() to A() \\ An array pointer can point to another array A=A() Print Dimension(A, 0) ' LBound (0 or 1), here 1 (was 0) \\ Because B$() is reference of A: Print Dimension(B$(), 0) ' LBound (0 or 1), here 1 (was 0) Print B$(1)=A$(1) Print B$(2)=A$(2) Print Dimension(C$(), 0) ' LBound (0 or 1), here 0 \\ change base preserve items Dim Base 1, C$(Dimension(C$(), 1)) Print Dimension(C$(), 0) ' LBound (0 or 1), here 1 (was 0) Print C$() ' prints Apple Orange Print Len(C$()) ' Len return all items of an array - can be 0 Dim K(1,1,1,1,1,1) ' Maximum 10 dimensions Print Len(K()=1 ' True </lang>
Maple
<lang maple>a := Array(["apple", "orange"]); numelems(a);</lang>
- Output:
a := [ "apple" "orange" ] 2
Mathematica /Wolfram Language
<lang Mathematica>Length[{"apple", "orange"}]</lang>
MATLAB / Octave
<lang Matlab>length({'apple', 'orange'})</lang> For arrays with more than one dimension, length reports the length of the larges dimension. The number of elements in a multi-dimensional array can be obtained with numel. <lang Matlab>numel({'apple', 'orange'; 'pear', 'banana'})</lang>
Mercury
<lang Mercury>:- module array_length.
- - interface.
- - import_module io.
- - pred main(io::di, io::uo) is det.
- - implementation.
- - import_module array, list.
main(!IO) :-
Array = array(["apples", "oranges"]), io.write_int(size(Array), !IO).</lang>
min
<lang min>("apple" "orange") size print</lang>
- Output:
2
MiniScript
<lang MiniScript> fruits = ["apple", "orange"] print fruits.len </lang>
MiniZinc
<lang MiniZinc> array[int] of int: arr = [1,2,3]; var int: size = length(arr);
solve satisfy;
output [show(size),"\n"]; </lang>
Nanoquery
<lang nanoquery>fruit = array(2) fruit[0] = "apple" fruit[1] = "orange" println len(fruit)
// outputs 2</lang>
Neko
<lang neko>var fruit = $array("apple", "orange");
$print($asize(fruit));</lang>
NewLISP
<lang newlisp>(println (length '("apple" "orange")))
- Nehal-Singhal 2018-05-25
(length '(apple orange))</lang>
NGS
<lang NGS>echo(len(['apple', 'orange']))
- same
echo(['apple', 'orange'].len())</lang>
Nim
<lang nim>let fruit = ["apple", "orange"] echo "The length of the fruit array is ", len(fruit)</lang>
- Output:
The length of the fruit array is 2
Oberon-2
<lang oberon2> MODULE ArrayLength; IMPORT
Strings, Out;
TYPE
String = POINTER TO ARRAY OF CHAR;
VAR
a: ARRAY 16 OF String;
PROCEDURE NewString(s: ARRAY OF CHAR): String; VAR
str: String;
BEGIN
NEW(str,Strings.Length(s) + 1);COPY(s,str^); RETURN str
END NewString;
PROCEDURE Length(a: ARRAY OF String): LONGINT; VAR
i: LONGINT;
BEGIN
i := 0; WHILE (a[i] # NIL) DO INC(i) END; RETURN i;
END Length;
BEGIN
a[0] := NewString("apple"); a[1] := NewString("orange"); Out.String("length: ");Out.Int(Length(a),0);Out.Ln
END ArrayLength. </lang>
- Output:
length: 2
Objeck
<lang objeck> class Test {
function : Main(args : String[]) ~ Nil { fruit := ["apples", "oranges"]; fruit->Size()->PrintLine(); }
}</lang>
OCaml
<lang OCaml> Array.length [|"apple"; "orange"|];; </lang>
Oforth
<lang Oforth>[ "apple", "orange" ] size</lang>
Ol
All of these methods are equivalent. <lang scheme> (print (vector-length (vector "apple" "orange"))) (print (vector-length #("apple" "orange"))) (print (vector-length ["apple" "orange"]))
(print (size #("apple" "orange"))) </lang>
Onyx
<lang onyx>[`apple' `orange'] length # leaves 2 on top of the stack</lang>
ooRexx
<lang oorexx> /* REXX */ a = .array~of('apple','orange') say a~size 'elements' Do e over a
say e End
Say "a[2]="a[2]</lang>
- Output:
2 elements apple orange a[2]=orange
PARI/GP
<lang parigp>array = ["apple", "orange"] length(array) \\ == 2
- array \\ == 2</lang>
The #
syntax is a handy shorthand. It usually looks best just on variables but it works on expressions too, possibly with parens to control precedence.
Both forms work on column vectors too, and also on strings and matrices. (For a matrix it is the number of columns.)
Pascal
<lang Pascal>
- !/usr/bin/instantfpc
//program ArrayLength;
{$mode objfpc}{$H+}
uses SysUtils, Classes;
const
Fruits : array[0..1] of String = ('apple', 'orange');
begin
WriteLn('Length of Fruits by function : ', Length(Fruits)); WriteLn('Length of Fruits by bounds : ', High(Fruits) - Low(Fruits) + 1);
END. </lang>
- Output:
./ArrayLength.pas Length of Fruits by function : 2 Length of Fruits by bounds : 2
Perl
The way to get the number of elements of an array in Perl is to put the array in scalar context.
<lang perl>my @array = qw "apple orange banana", 4, 42;
scalar @array; # 5 0 + @arrray; # 5 . @array; # "5" my $elems = @array; # $elems = 5
scalar @{ [1,2,3] }; # [1,2,3] is a reference which is already a scalar
my $array_ref = \@array; # a reference scalar @$array_ref;
- using subroutine prototypes, not generally recommended
- and not usually what you think they are
sub takes_a_scalar ($) { my ($a) = @_; return $a }
takes_a_scalar @array;
- the built-ins can also act like they have prototypes</lang>
A common mistake is to use length
which works on strings not arrays.
So using it on an array, as a side-effect, actually gives you a number which represents the order of magnitude.
<lang perl>length . @array; # 1 length @array; # 1
print '0.', scalar @array, 'e', length @array, "\n"; # 0.5e1
@array = 1..123; print '0.', scalar @array, 'e', length @array, "\n"; # 0.123e3
print 'the length of @array is on the order of '; print 10 ** (length( @array )-1); # 100 print " elements long\n";</lang>
Phix
constant fruits = {"apple","orange"} ?length(fruits)
- Output:
2
Phixmonti
<lang Phixmonti>"apple" "orange" stklen tolist len print</lang> With syntactic sugar <lang Phixmonti>include ..\Utilitys.pmt ( "apple" "orange" ) len print</lang>
- Output:
2
PHP
<lang php>print count(['apple', 'orange']); // Returns 2</lang>
Picat
<lang>main =>
L = ["apple", "orange"], println(len(L))), println(length(L)), println(L.len), println(L.length).</lang>
- Output:
2 2 2 2
PicoLisp
<lang PicoLisp>: (length '(apple orange)) -> 2
- </lang>
Pike
<lang pike>void main() {
array fruit = ({ "apple", "orange" }); write("%d\n", sizeof(fruit));
}</lang>
- Output:
2
PL/I
<lang pli> p: Proc Options(main);
Dcl a(2) Char(6) Varying Init('apple','orange'); Put Edit('Array a has',(hbound(a)-lbound(a)+1),' elements.') (Skip,a,f(2),a); Put Skip Data(a); End;</lang>
- Output:
Array a has 2 elements. A(1)='apple' A(2)='orange';
Plorth
<lang plorth>["apple", "orange"] length println</lang>
Pony
<lang pony> actor Main
new create(env:Env)=> var c=Array[String](2) c.push("apple") c.push("orange") env.out.print("Array c is " + c.size().string() + " elements long!")
</lang>
Potion
<lang potion>("apple", "orange") length print</lang>
PowerShell
<lang PowerShell> $Array = @( "Apple", "Orange" ) $Array.Count $Array.Length</lang>
- Output:
2 2
Processing
<lang Processing> String[] arr = {"apple", "orange"}; void setup(){
println(arr.length);
} </lang>
- Output:
2
Processing Python mode
<lang python> arr = ['apple', 'orange'] # a list for an array
def setup():
println(len(arr))
</lang>
- Output:
2
Prolog
<lang Prolog>| ?- length(["apple", "orange"], X).
X = 2
yes</lang>
PureBasic
<lang PureBasic> EnableExplicit Define Dim fruit$(1); defines array with 2 elements at indices 0 and 1 fruit$(0) = "apple" fruit$(1) = "orange" Define length = ArraySize(fruit$()) + 1; including the element at index 0 If OpenConsole()
PrintN("The length of the fruit array is " + length) PrintN("") PrintN("Press any key to close the console") Repeat: Delay(10) : Until Inkey() <> "" CloseConsole()
EndIf </lang>
- Output:
The length of the fruit array is 2
An abbreviated form of the above, not printing to console/terminal <lang PureBasic> Dim fruit$(1); defines array with 2 elements at indices 0 and 1 fruit$(0) = "apple" fruit$(1) = "orange" Debug ArraySize(fruit$()) + 1 ;the number of elements is equal to the size + 1. For example: Dim a(2) contains 3 elements from a(0) to a(2) for a size of 2. </lang>
- Output:
2
Python
<lang python>>>> print(len(['apple', 'orange'])) 2 >>> </lang>
QB64
<lang QB64> Dim max As Integer, Index As Integer Randomize Timer max = Int(Rnd * 10) + 1 Dim StringAr(1 To max) As String
For Index = 1 To max
If Int(Rnd * 6) + 1 <= 3 Then StringAr(Index) = "Apple" Else StringAr(Index) = "orange"
Next Print UBound(Stringar) End </lang>
Quackery
<Lang Quackery> $ "apples" $ "oranges" 2 pack size echo</lang>
- Output:
2
R
<lang R> a <- c('apple','orange') # create a vector containing "apple" and "orange" length(a) </lang>
- Output:
[1] 2
Racket
<lang racket>#lang racket/base (length '("apple" "orange")) ;; list (vector-length #("apple" "orange")) ;; vector</lang>
- Output:
2 2
Raku
(formerly Perl 6)
To get the number of elements of an array in Raku you put the array in a coercing Numeric context, or call elems
on it.
<lang perl6> my @array = <apple orange>;
say @array.elems; # 2 say elems @array; # 2 say + @array; # 2 say @array + 0; # 2 </lang>
Watch out for infinite/lazy arrays though. You can't get the length of those.
<lang perl6>my @infinite = 1 .. Inf; # 1, 2, 3, 4, ...
say @infinite[5000]; # 5001 say @infinite.elems; # Throws exception "Cannot .elems a lazy list" </lang>
Red
<lang Red>length? ["apples" "oranges"] == 2</lang>
Relation
<lang Relation> relation fruit insert "apples" insert "oranges" project fruit count print </lang>
fruit_count |
---|
2 |
ReScript
<lang rescript>let fruits = ["apple", "orange"]
Js.log(Js.Array.length(fruits))</lang>
<lang html><!DOCTYPE html> <html> <head> <title>ReScript: Array.length()</title> <style rel="stylesheet" type="text/css"> body { color:#EEE; background-color:#888; } </style> <script>var exports = {};</script> <script src="./arrlen.js"></script> </head> <body>
</body> </html></lang>
- Output:
// Generated by ReScript, PLEASE EDIT WITH CARE 'use strict'; var fruits = [ "apple", "orange" ]; console.log(fruits.length); exports.fruits = fruits; /* Not a pure module */
REXX
<lang rexx>/* REXX ----------------------------------------------
- The compond variable a. implements an array
- By convention, a.0 contains the number of elements
- ---------------------------------------------------*/
a.=0 /* initialize the "array" */ call store 'apple' Call store 'orange' Say 'There are' a.0 'elements in the array:' Do i=1 To a.0
Say 'Element' i':' a.i End
Exit store: Procedure Expose a. z=a.0+1 a.z=arg(1) a.0=z Return</lang>
- Output:
There are 2 elements in the array: Element 1: apple Element 2: orange
Ring
<lang python>See len(['apple', 'orange']) # output = 2 </lang>
Robotic
As stated before in the arrays section on this Wiki, there is no functions listed for the manipulation/status of arrays. The best way we can count for length in an array is to have a variable keep track of it.
Example 1: <lang robotic> set "index" to 0 set "$array&index&" to "apple" inc "index" by 1 set "$array&index&" to "orange"
- "Array length: ('index' + 1)"
</lang>
Example 2: <lang robotic> set "index" to 0 set "local1" to random 1 to 99
- "rand"
set "array&index&" to random 0 to 99 inc "index" 1 dec "local1" 1 if "local1" > 1 then "rand"
- "Array length: ('index')"
</lang>
Ruby
<lang ruby>puts ['apple', 'orange'].length # or .size</lang>
Rust
By default arrays are immutable in rust.
<lang rust> fn main() {
let array = ["foo", "bar", "baz", "biff"]; println!("the array has {} elements", array.len());
} </lang>
Scala
<lang scala> println(Array("apple", "orange").length) </lang>
Scheme
Using Scheme's vector type as an equivalent to an array:
<lang scheme> (display (vector-length #("apple" "orange"))) </lang>
Seed7
The function length determines the length of an array. <lang seed7>$ include "seed7_05.s7i";
const array string: anArray is [] ("apple", "orange");
const proc: main is func
begin writeln(length(anArray)); end func;</lang>
SenseTalk
<lang sensetalk>put ("apple", "orange", "pear", "banana", "aubergine") into fruits put the number of items in fruits</lang>
Shen
<lang shen> \\ Using a vector \\ @v creates the vector \\ <> ends the vector \\ limit returns the length of a vector \\ apple and orange are symbols (vs strings) in this case. (limit (@v apple orange <>))
\\ As an list
(length [apple orange])
</lang>
Sidef
<lang ruby>var arr = ['apple', 'orange']; say arr.len; #=> 2 say arr.end; #=> 1 (zero based)</lang>
Simula
<lang simula>COMMENT ARRAY-LENGTH; BEGIN
INTEGER PROCEDURE ARRAYLENGTH(A); TEXT ARRAY A; BEGIN ARRAYLENGTH := UPPERBOUND(A, 1) - LOWERBOUND(A, 1) + 1; END ARRAYLENGTH;
TEXT ARRAY A(1:2); INTEGER L; A(1) :- "APPLE"; A(2) :- "ORANGE"; L := ARRAYLENGTH(A); OUTINT(L, 0); OUTIMAGE;
END </lang>
- Output:
2
Smalltalk
<lang smalltalk> a := #('apple' 'orange'). a size</lang>
SNOBOL4
<lang SNOBOL4> ar = ARRAY('2,2')
ar<1,1> = 'apple' ar<1,2> = 'first' ar<2,1> = 'orange' ar<2,2> = 'second' OUTPUT = IDENT(DATATYPE(ar), 'ARRAY') PROTOTYPE(ar)
end</lang>
- Output:
2,2
SPL
<lang spl>a = ["apple","orange"]
- .output("Number of elements in array: ",#.size(a,1))</lang>
- Output:
Number of elements in array: 2
SQL
<lang sql>SELECT COUNT() FROM (VALUES ('apple'),('orange'));</lang>
Standard ML
<lang sml>let
val a = Array.fromList ["apple", "orange"]
in
Array.length a
end;</lang>
Stata
String data may be stored either in a Stata dataset or in a Mata matrix, not in a Stata matrix, which may hold only numeric data. A list of strings may also be stored in a Stata macro.
Dimensions of a dataset
<lang stata>clear input str10 fruit apple orange end
di _N di c(N) " " c(k)</lang>
Length of a macro list
Use either the sizeof macro list function or the word count extended macro function. Notice that the argument of the former is the macro name, while the argument of the latter is the macro contents.
<lang stata>local fruits apple orange di `: list sizeof fruits' di `: word count `fruits</lang>
Mata
For a Mata array, use rows and similar functions:
<lang stata>mata a=st_sdata(.,"fruit") rows(a) cols(a) length(a) end</lang>
Swift
<lang Swift>let fruits = ["apple", "orange"] // Declare constant array literal let fruitsCount = fruits.count // Declare constant array length (count)
print(fruitsCount) // Print array length to output window</lang>
- Output:
2
Symsyn
<lang Symsyn> | Symsyn does not support Array of Strings | The following code for an Array of Integers
A : 125 0
#A []
| shows 125
| A list of fixed length strings can be handled this way
S : 'apple ' : 'orange'
div #S 6 sz sz []
| shows 2 </lang>
Tailspin
<lang tailspin> ['apple', 'orange'] -> $::length -> !OUT::write </lang>
- Output:
2
Tcl
<lang tcl>;# not recommended: set mylistA {apple orange} ;# actually a string set mylistA "Apple Orange" ;# same - this works only for simple cases
set lenA [llength $mylistA] puts "$mylistA : $lenA"
- better: to build a list, use 'list' and/or 'lappend':
set mylistB [list apple orange "red wine" {green frog}] lappend mylistB "blue bird"
set lenB [llength $mylistB] puts "$mylistB : $lenB" </lang>
- Output:
Apple Orange : 2 apple orange {red wine} {green frog} {blue bird} : 5
TI-83 BASIC
Use function dim()
.
<lang ti83b>{1,3,–5,4,–2,–1}→L1
dim(L1)</lang>
- Output:
6
Transd
<lang scheme>#lang transd
MainModule : {
_start: (lambda (with v ["apple", "orange"] (lout (size v)) ) (lout (size ["apple", "orange"])) )
}</lang>
- Output:
2 2
UNIX Shell
<lang bash>#!/bin/bash array=("orange" "apple") echo "${#array[@]}"</lang>
- Output:
2
Ursa
> decl string<> stream > append "two" "strings" stream > out (size stream) endl console 2 > out (size "test string") endl console 11 >
Vala
<lang vala>void main() {
string[] fruit = {"apple", "orange"}; stdout.printf("%d\n", fruit.length);
}</lang>
Note that any of the following array declarations could be used:
<lang vala> var fruit = new string[] { "apple", "orange" }; string[] fruit = new string[] { "apple", "orange" }; string[] fruit = { "apple", "orange" }; </lang>
A shorter variant could also have been used:
<lang vala> void main() {
stdout.printf("%d\n", new string[] {"apples", "orange"}.length);
} </lang>
VBA
One-liner. Assumes array lower bound, which is not always safe. <lang vb>Debug.Print "Array Length: " & UBound(Array("apple", "orange")) + 1</lang>
Works regardless of lower bound: <lang vb>Dim funkyArray(7 to 8) As String
Public Function SizeOfArray(ar As Variant) As Long
SizeOfArray = UBound(ar) - LBound(ar) + 1
End Function
'call the function Debug.Print "Array Length: " & SizeOfArray(funkyArray)</lang>
- Output:
In this instance, same output for both.
Array Length: 2
VBScript
<lang vb>arr = Array("apple","orange") WScript.StdOut.WriteLine UBound(arr) - LBound(arr) + 1 </lang>
- Output:
2
Visual Basic
The amount of elements in an array in Visual Basic is computed via the upper bound and lower bound indices. In Visual Basic the indices of arrays have to be numeric, but it is even possible to have negative values for them. Of course the element numbering is continuous.
<lang vb> ' declared in a module Public Function LengthOfArray(ByRef arr As Variant) As Long
If IsArray(arr) Then LengthOfArray = UBound(arr) - LBound(arr) + 1 Else LengthOfArray = -1 End If
End Function
' somewhere in the programm ' example 1
Dim arr As Variant arr = Array("apple", "orange") Debug.Print LengthOfArray(arr) ' prints 2 as result
' example 2
Dim arr As Variant ReDim arr(-2 To -1) arr(-2) = "apple" arr(-1) = "orange"
Debug.Print LengthOfArray(arr) ' prints 2 as result
</lang>
Visual Basic .NET
<lang vbnet>Module ArrayLength
Sub Main() Dim array() As String = {"apple", "orange"} Console.WriteLine(array.Length) End Sub
End Module </lang>
- Output:
2
Vlang
A len property is maintained for all V arrays. <lang go>// V, array length // Tectonics: v run array-length.v module main
// access array length pub fn main() {
arr := ["apple", "orange"] println(arr.len)
}</lang>
- Output:
prompt$ v run array-length.v 2
WDTE
<lang wdte>let io => import 'io'; let a => ['apple'; 'orange']; len a -- io.writeln io.stdout;</lang>
Wren
<lang ecmascript>var arr = ["apple", "orange"] System.print(arr.count)</lang>
- Output:
2
XLISP
<lang lisp>(vector-length #("apple" "orange"))</lang>
Yabasic
<lang yabasic> dim fruta$(3) read fruta$(1), fruta$(2), fruta$(3) data "apple", "orange", "pear"
print arraysize(fruta$(),1) print fruta$(2) end </lang>
3 orange
Z80 Assembly
Arrays don't have an "end" as defined by the language, so there are a couple ways to mark the end of an array. One is with a null terminator, and the other is with a pre-defined size byte stored at the beginning. Using a null terminator isn't the best choice for a general-purpose array since it means your array cannot contain that value anywhere except at the end. However, since having the size already determined defeats the purpose of this task, the null-terminator method will be used for this example.
The simplest way to implement an array of variable-length strings is to have the array contain pointers to said strings rather than the strings themselves. That way, the elements of the array are of equal length, which makes any array much easier to work with.
<lang z80> org &8000 ld hl,TestArray call GetArrayLength_WordData_NullTerminated
call Monitor ;show registers to screen, code omitted to keep this example short
ReturnToBasic: RET
GetArrayLength_WordData_NullTerminated: push hl ;we'll need this later loop_GetArrayLength_WordData_NullTerminated ld a,(hl) ;get the low byte ld e,a ;stash it in E inc hl ;next byte ld a,(hl) ;get the high byte dec hl ;go back to low byte, otherwise our length will be off. or a ;compare to zero. This is a shorter and faster way to compare A to zero than "CP 0"
jr nz,keepGoing cp e ;compare to E jr z,Terminated_GetArrayLength ;both bytes were zero. KeepGoing: inc hl inc hl ;next word jp loop_GetArrayLength_WordData_NullTerminated ;back to start Terminated_GetArrayLength: pop de ;original array address is in DE ;or a ;normally it's best to clear the carry, but in this situation execution only arrives here after a compare that
;resulted in an equality to zero, which means the carry is guaranteed to be cleared.
sbc hl,de ;there is no sub hl,de; only sbc
srl h rr l ;divide HL by 2, since each element is 2 bytes.
ret ;returns length in hl
TestArray: word Apple,Orange byte 0,0
Apple: byte "Apple",0 Orange: byte "Orange",0</lang>
- Output:
(HL contains length of the array) HL:0002
zkl
zkl doesn't support arrays natively, use lists instead. <lang zkl>List("apple", "orange").len().println() //-->2, == L("apple", "orange") T("apple", "orange").len().println() //-->2, read only list (ROList) </lang>
Zig
<lang zig>const std = @import("std");
pub fn main() !void {
// left hand side type can be ommitted const fruit: [2][]const u8 = [_][]const u8{ "apples", "oranges" }; const stdout_wr = std.io.getStdOut().writer(); // slices and arrays have an len field try stdout_wr.print("fruit.len = {d}\n", .{fruit.len});
}</lang>
Zoea
<lang Zoea> program: array_length
input: [a,b,c] output: 3
</lang>
Zoea Visual
zonnon
<lang zonnon> module AryLength; type Vector = array 12 of string; Matrix = array *,* of string; var a: Vector; b: Matrix; begin writeln(len(a):4); (* len(a) = len(a,0) *)
b := new Matrix(10,11); writeln(len(b,0):4); (* first dimension *) writeln(len(b,1):4) (* second dimension *) end AryLength. </lang>
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