IF Keyword

IF expression THEN statement ELSE statement
 
IF expression THEN
    statements
ENDIF
 
IF expression THEN
    statements
ELSE
    statements
ENDIF

Executes statements if an expression evaluates to true. You can write IF as a single-line statement (with one statement after THEN and, optionally, one after ELSE), or as a multi-line block closed by ENDIF.

Remarks

Multi-line blocks must be closed with ENDIF.

END IF (with a space) is not recognised.

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Comparison operators

Operator	Meaning
>	Greater than
<	Less than
>=	Greater than or equal to
<=	Less than or equal to
=	Equal to
<>	Not equal to

These operators produce a boolean result suitable for IF.

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Forms and examples

Single-line (with ELSE)

IF X > 0 THEN PRINT "POSITIVE" ELSE PRINT "NON-POSITIVE"

Single-line (no ELSE)

IF READY THEN PRINT "GO"

Multi-line (no ELSE)

IF SCORE >= 100 THEN
    PRINT "LEVEL UP"
ENDIF

Multi-line (with ELSE)

IF NAME$ = "ADMIN" THEN
    PRINT "WELCOME"
ELSE
    PRINT "ACCESS DENIED"
ENDIF

Nested IF

IF A > 0 THEN
    IF B > 0 THEN
        PRINT "BOTH POSITIVE"
    ELSE
        PRINT "A POSITIVE ONLY"
    ENDIF
ELSE
    PRINT "A NOT POSITIVE"
ENDIF

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Notes

• In the single-line form, the THEN and optional ELSE parts each allow one statement. Use the multi-line form for multiple statements.
• IF blocks may be nested freely; ENDIF matches the nearest unmatched IF.
• Use parentheses to make complex conditions explicit: IF (A > 0) AND (B < 10) THEN ... (where supported by your operators).

See also: ELSE · ENDIF