[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] Reference for unit 'System' (#rtl)

Exit

Exit current subroutine.

Declaration

Source position: line 0

procedure Exit(

  const X: TAnyType

);

procedure Exit;

Description

Exit exits the current subroutine, and returns control to the calling routine. If invoked in the main program routine, exit stops the program. The optional argument X allows to specify a return value, in the case Exit is invoked in a function. The function result will then be equal to X.

Errors

None.

See also

Halt

  

Stop program execution.

Example

Program Example21;

{ Program to demonstrate the Exit function. }

Procedure DoAnExit (Yes : Boolean);

{ This procedure demonstrates the normal Exit }

begin
  Writeln ('Hello from DoAnExit !');
  If Yes then
    begin
    Writeln ('Bailing out early.');
    exit;
    end;
  Writeln ('Continuing to the end.');
end;

Function Positive (Which : Integer) : Boolean;

{ This function demonstrates the extra FPC feature of Exit :
  You can specify a return value for the function }

begin
  if Which>0 then
    exit (True)
  else
    exit (False);
end;

begin
  { This call will go to the end }
  DoAnExit (False);
  { This call will bail out early }
  DoAnExit (True);
  if Positive (-1) then
    Writeln ('The compiler is nuts, -1 is not positive.')
  else
    Writeln ('The compiler is not so bad, -1 seems to be negative.');
end.
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