UniBasic Commands Reference - Rocket Software

Parameters
The following table describes each parameter of the syntax.
Parameter Description
expr Specifies a numeric expression. UniData evaluates the expression, and then
truncates it to an integer. Control passes to a subroutine based on the
following rules.
If expr is less than or equal to 1, UniData transfers program control to the
subroutine starting at the first label in the list. If the number is 2, UniData
transfers control to the subroutine starting at the second label, and so forth.
If expr is higher than the number of labels, UniData transfers control to the
last label in the list.
If expr is nonnumeric, control transfers to the first label.
label Specifies a subroutine label or multiple subroutine labels.
: Optional. A colon is required to identify a nonnumeric label in the statement
label itself only, not in the reference to it in the ON/GOSUB statement.
ON/GOSUB Parameters
Examples
In the following example, the program segment divides the variable BALANCE by
100. If the result is less than or equal to 1, the program transfers control to subroutine
U100. If the value is 2 or 3, it transfers control to U200 or U300 respectively. If the
value is greater than or equal to 4, UniData transfers control to subroutine U400.
ON BALANCE/100 GOSUB U100,U200,U300,U400
In the next example, the program segment transfers control to a subroutine after
prompting the user for a screen item to modify. In this case, depending on the number
the user enters, UniData transfers control to one of the five subroutines in the
GOSUB clause. If the user response is nonnumeric or less than 1, UniData transfers
control to the first subroutine. If the user enters a value greater than 5, UniData
transfers control to the last subroutine (500).
GOSUB DISPLAY.SCREEN:
PRINT "Enter Item number to modify (1-5): ":
INPUT ACTION
ON ACTION GOSUB 100,200,300,400,500
ON/GOSUB 1-530