Branch to one of several specified lines, depending on the value of an expression.
Syntax
On expression GoSub destinationlist
On expression GoTo destinationlist
The On...GoSub and On...GoTo statement syntax has these parts:
| Part | Description |
|---|---|
| expression | Required. Any numeric expression that evaluates to a whole number between 0 and 255, inclusive. If expression is any number other than a whole number, it is rounded before it is evaluated. |
| destinationlist | Required. List of line numbers or line labels separated by commas. |
Remarks
The value of expression determines which line is branched to in destinationlist. If the value of expression is less than 1 or greater than the number of items in the list, one of the following results occurs:
| If expression is | Then |
|---|---|
| Equal to 0 | Control drops to the statement following On...GoSub or On...GoTo. |
| Greater than number of items in list | Control drops to the statement following On...GoSub or On...GoTo. |
| Negative | An error occurs. |
| Greater than 255 | An error occurs. |
You can mix line numbers and line labels in the same list. Use as many line labels and line numbers as you like with On...GoSub and On...GoTo. However, if you use more labels or numbers than fit on a single line, you must use the line-continuation character to continue the logical line onto the next physical line.
Select Case provides a more structured and flexible way to perform multiple branching.
Example
This example uses the On...GoSub and On...GoTo statements to branch to subroutines and line labels, respectively.
Sub OnGosubGotoDemo()
Dim Number, MyString
Number = 2 ' Initialize variable.
' Branch to Sub2.
On Number GoSub Sub1, Sub2 ' Execution resumes here after
' On...GoSub.
On Number GoTo Line1, Line2 ' Branch to Line2.
' Execution does not resume here after On...GoTo.
Exit Sub
Sub1:
MyString = "In Sub1": Return
Sub2:
MyString = "In Sub2": Return
Line1:
MyString = "In Line1"
Line2:
MyString = "In Line2"
End Sub