ListIndexBefore
Type
operator
Summary
Find the first or last occurrence of Needle within the head of Haystack Target:An expression which evaluates to a list.
Syntax
the ( first | last ) index of <Needle> before <Before> in <Haystack>
Description
Use the index of⦠before to find where particular elements occur
within a list. Haystack is scanned for an element that is equal to
Needle, stopping before the position Before, and the position of
the element found is returned. If no element of Haystack is equal
to Needle, the return value is 0. If neither "first" nor "last" is
specified, the last matching element is found.
Parameters
| Name | Type | Description |
|---|---|---|
Needle | An expression which evaluates to any value. | |
Before | An expression which evaluates to a valid index in Target. |
Examples
variable tVar as List
variable tOffset as Number
put ["a", "b", "c", "d", "b"]
put the index of "b" before 2 in tVar into tOffset
--tOffset contains 0
put the first index of "b" before 5 in tVar into tOffset
--tOffset contains 2