IF               Initiate Conditional Block                    MASM Directive

IF expression

Initiates a conditional block, causing the assembly of statements up
to the optional ELSE directive, provided that expression is true
(evaluates to a nonzero value).

Notes:     IF directives may be nested to 255 levels.

The statements following IF and ELSE can be other IF
conditional blocks.

If the condition if false (evaluates to a zero value)
and an ELSE directive is included, the statements
between the ELSE and ENDIF will be assembled.

A nested ELSE directive is matched with the nearest IF
directive that does not have an ELSE directive.

The expression for the IFE directive must resolve to an
absolute value and must not be a forward reference.

See also: IFE
See also: ELSE
See also: ENDIF

IF Initiate Conditional Block