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if Boolean expression then statement |
if Boolean expression then statement1 else statement2 |
The `if ... then' statement executes statement1 depending on `Boolean expression' being true. If `else' is specified, it continues executing statement2 instead.
`if' is defined in ISO-7185 Pascal and supported by all Pascal variants.
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. |
section 8.1.7.3 if Statement, section 9.68 else, section 9.274 then