ListExists Function

Indicates whether an element is present in the list and has a value.

Synopsis

ListExists(list, position)

Arguments

The ListExists function has the following parameters:

list	An expression that evaluates to a valid list.
position	An expression interpreted as a position

Remarks

The ListExists function returns a value of 1 if the element at the indicated position is in the list and has a data value. Otherwise ListExists returns zero.

Examples

The following examples demonstrates how to use the ListExists function:

Erase Y 'Y is now undefined

myList = ListBuild("Red", "Blue", , Y, "Yellow")

Println ListExists(myList, 2) '1
Println ListExists(myList, 3) '0
Println ListExists(myList, 4) '0