Policy Server Guides › Policy Server Configuration Guide › Attributes and Expressions Reference › Functions Available within Expressions › FILTER Function--Test Set Elements

FILTER Function--Test Set Elements

The FILTER function compares each element in the specified set to the specified pattern and returns a new set containing only the elements that match the pattern. If the optional NOT operator is included, the FILTER function returns a new set containing only the elements that do not match the pattern.

Syntax

The FILTER function has the following format:

FILTER(set, [NOT ]pattern)

Parameters

The FILTER function accepts the following parameters:

set (string)

Specifies a string of elements that are separated by the caret character: 'element1^element2'. Each element is a string.

pattern (string)

Specifies a pattern of characters. A pattern can include single characters, ranges of characters, or both. A range of characters is expressed as two characters separated by a hyphen. The following are examples of valid character ranges: 0-9, a-z, and A-Z. The pattern parameter can also include characters that are reserved and have special meanings. The reserved characters are:

NOT (operator)

(Optional) If the NOT operator is included, the function returns a new set containing only the elements that do not match the pattern.

Return Value

The FILTER function returns a string of elements separated by the caret character: 'element1^element2'. Each element is a string.

Example

Return_value=FILTER('Faith^Earl^Emilie^Fred', 'E*')
Return_value='Earl^Emilie'

Return_value=FILTER('Faith^Earl^Emilie^Fred', NOT 'E*')
Return_value='Faith^Fred'