substring-before

The substring-before function returns a string that is the part of a given string before a given substring.

Syntax

substring-before( haystack, needle )

Arguments

haystack

The string to be evaluated. Part of this string will be returned.

needle

The substring to search for. Everything before the first occurrence of*needle* in*haystack* will be returned.

Returns

A string.

Examples

XPath Example Output
substring-before('aa-bb','-') aa
substring-before('aa-bb','a') (empty string)
substring-before('aa-bb','b') aa-
substring-before('aa-bb','q') (empty string)

Defined

Gecko support

Supported.