Node:if, Next:, Previous:High, Up:Reference



if

Synopsis


if Boolean_expression then
  statement
or with an alternative statement:
if Boolean_expression then
  statement1
else
  statement2

Description

The if ... then statement executes statement1 depending on Boolean expression being true. If else is specified, it continues executing statement2 instead.

Conforming to

if is defined in ISO 7185 Pascal and supported by all Pascal variants.

Example


program IfDemo;
var
  Foo, Bar: Boolean;
begin
  Foo := True;
  Bar := False;
  if ((1 = 1) or (2 = 3)) and (Foo = not Bar) then
    begin
      { This is executed if either Foo is true but not Bar or vice versa }
      WriteLn ('Either Foo or Bar is true.');
      if Bar then
        WriteLn ('You will see this text if Bar is true.')
    end
  else { This whole `else' branch is not executed }
    if 1 = 1 then
      if True = False then
        WriteLn ('This text is never written on screen.')
      else  { Note: This ``else'' belongs to ``if True = False'' }
        WriteLn ('This text is never written on screen as well.')
    else  { Note: This ``else'' belongs to ``if 1 = 1'' }
      WriteLn ('Nor is this.')
end.

See also

Keywords, if Statement, else, then