236
____________________________________________________________________
Flow control statement
ON…GOSUB, ON…GOTO
Branches to one of specified labels according to the value of an expression.
____________________________________________________________________
Syntax:
Syntax:Syntax:
Syntax:
Syntax 1:
ON expression GOSUB label [,label...]
Syntax 2:
ON expression GOTO label [,label...]
Parameter:
Parameter:Parameter:
Parameter:
expression
A numeric expression which returns a value from 1 to 255.
Description:
Description:Description:
Description:
ON...GOSUB or ON...GOTO block branches to a label in the label list according to the
value of expression.
• If expression has the value 3, for example, the target label is the third one in the label
list counting from the first.
• If expression has the value 0 or a value greater than the number of labels in the label
list, execution of the ON ..GOSUB or ON ..GOTO block causes no run-time error and
passes control to the subsequent statement.
• You can specify any number of labels so long as a statement block does not exceed
one program line (512 characters).
• You can nest ON...GOSUB statements to a maximum of 10 levels.
• When using the GOSUB statement together with block-structured statements(DEF
FN ..END DEF, FOR ..NEXT, FUNCTION ..END FUNCTION,
IF ..THEN ...ELSE ..END IF, SELECT ..CASE ..END SELECT, SUB ..END SUB
and WHILE ..WEND), you can nest them to a maximum of 30 levels.
• You can use ON ..GO TO instead of ON ..GOTO.
Comentarios a estos manuales