Effect

Checks if a condition has been met and jumps to the number line specified after GOTO. Optionally, if the condition has not been met the instruction(s) after ELSE will be run.

Note: If you use the Exprif BASIC extension, no need to use this instruction!

Syntaxes

• IF <ConditionExpression> GOTO <LineNumber> ELSE <LineNumber>
• IF <ConditionExpression> GOTO <LineNumber> ELSE <BASICinstruction>:<BASICinstruction>:...

Parameters

<ConditionExpression> is an expression false (whose result is zero) or true (whose result is non-zero). For example, the expression A<>9 is equal to 0 if A is different from 9 otherwise the result is -1.

<LineNumber> is a line number of the program in memory.

<BASICinstruction> can be any MSX-BASIC instruction. When there are several BASIC instructions, they must be separated by the character colon.

ELSE can be omitted when it is not followed by one or more BASIC instructions or a program line number, that will be executed when the condition is false.

Examples

10 A=1: IF A GOTO 30
20 PRINT "A=0":END
30 PRINT "A is different from 0":END
 
RUN

A is different from 0

10 CLS
20 PRINT "Hello!"
30 TIME = 0
40 IF INKEY$="" GOTO 40
50 IF TIME <4 GOTO 50
60 IF INKEY$="" GOTO 60 ELSE 20

Related To

IF...THEN...ELSE

Compatibility

MSX-BASIC 1.0 or higher