Determine if a string is numeric

Determine if a string is numeric
You are encouraged to solve this task according to the task description, using any language you may know.

Demonstrates how to implement a custom IsNumeric method.

Ada

The first file is the package interface containing the declaration of the Is_Numeric function.

package Numeric_Tests is
   function Is_Numeric(Item : in String) return Boolean;
end Numeric_Tests;

The second file is the package body containing the implementation of the Is_Numeric function.

package body Numeric_Tests is

   ----------------
   -- Is_Numeric --
   ----------------

   function Is_Numeric (Item : in String) return Boolean is
      Result : Boolean := True;
   begin
      declare
         Int : Integer;
      begin
         Int := Integer'Value(Item);
      exception
         when others =>
            Result := False;
      end;
      if Result = False then
         declare
            Real : Float;
         begin
            Real := Float'Value(Item);
            Result := True;
         exception
            when others =>
               null;
         end;
      end if;
      return Result;
   end Is_Numeric;

end Numeric_Tests;

The last file shows how the Is_Numeric function can be called.

with Ada.Text_Io; use Ada.Text_Io;
with Numeric_Tests; use Numeric_Tests; 

procedure Isnumeric_Test is
   S1 : String := "152";
   S2 : String := "-3.1415926";
   S3 : String := "Foo123";
begin
   Put_Line(S1