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 known 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