Determine if a string is numeric

Demonstrates how to implement a custom IsNumeric method.

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

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