ON...GOTO

ON...GOTO is a control-flow statement that branches to a line or label in a list depending on a numerical expression.

ON numericalExpression GOTO labelOrNumber[,labelOrNumber][,...]

• numericalExpression represents the line or label that the program should branch to: 1 branches to the first line or label in the list, 2 branches to the second, etc.
• The procedure must be used after the number value is determined or in a loop to monitor current user events.
• Note: SELECT CASE provides a much more convenient way of doing this task.

• In QuickBASIC 4.5 the list could contain a maximum of 60 line numbers or labels, while QB64 has no limit.

Changing the program flow when a value is not 0.

CLS
a = 2
ON a GOTO hello, hereweare, 143
END
hello:
PRINT "you don't get to see this!"
END
hereweare:
PRINT "And here we are..."
END
143
PRINT "you don't get to see this neither..."
END 

And here we are...

Explanation: Since a equals 2 it goes to the second item in the list (hereweare) and branches to there. Try changing *a' to 1 or 3.

• ON...GOSUB
• GOTO
• GOSUB
• SELECT CASE