If


Statement If


There are two forms of IF statement:


IF...THEN and the IF...THEN...ELSE as a single line statement.


IF...THEN...ENDIF and the IF...THEN...ELSE ...ENDIF as a multi line (or block) statement.


Single Line form

IF expression THEN statement1 ELSE statement2


Where expression returns a boolean value. If expression is true (non zero result), then statement1 is executed; otherwise statement2, following the else clause is executed.


Multi-Line (Block) form

IF expression THEN

statement

statement

statement

ELSE

statement

statement

ENDIF


For example, as a single line statement

IF J <> 0 then Result = I/J else Result = 0 ' Avoid a divide by zero error.


Written as a block statement (therefore requiring the ENDIF keyword):

IF J <> 0 THEN ' Nothing must appear after THEN except a comment

Result = I / J

ELSE ' Nothing must appear after ELSE except a comment

Result = 0

ENDIF


Most programming books and modern languages prefer the Block (Multi-line) form for the IF statement. It is more structured and easier to follow.

Since there is no statement separator provided in this scripting language, only a single THEN statement followed by ELSE and another single statement is possible in the single line form.


See Also:

Statements