extract_all()

Get all matches for a regular expression from a source string. Optionally, retrieve a subset of matching groups.

print extract_all(@"(\d+)", "a set of numbers: 123, 567 and 789") // results with the dynamic array ["123", "567", "789"]

Deprecated aliases: extractall()

Syntax

extract_all(regex, [captureGroups,] source)

Arguments

Argument Description Required or Optional
regex A regular expression containing between one and 16 capture groups. Example of a valid regex: @"(\d+)". Example of an invalid regex: @"\d+" Required
captureGroups A dynamic array constant that indicates the capture group to extract. Valid values are from 1 to the number of capturing groups in the regular expression. Named capture groups are allowed as well (See Examples) Optional
source A string to search Required

Returns

  • If regex finds a match in source: Returns dynamic array including all matches against the indicated capture groups captureGroups, or all of capturing groups in the regex.
  • If number of captureGroups is 1: The returned array has a single dimension of matched values.
  • If number of captureGroups is more than 1: The returned array is a two-dimensional collection of multi-value matches per captureGroups selection, or all capture groups present in the regex if captureGroups is omitted.
  • If there's no match: null.

Examples

Extract a single capture group

Returns hex-byte representation (two hex-digits) of the GUID.

print Id="82b8be2d-dfa7-4bd1-8f63-24ad26d31449"
| extend guid_bytes = extract_all(@"([\da-f]{2})", Id) 
ID guid_bytes
82b8be2d-dfa7-4bd1-8f63-24ad26d31449 ["82","b8","be","2d","df","a7","4b","d1","8f","63","24","ad","26","d3","14","49"]

Extract several capture groups

Uses a regular expression with three capturing groups to split each GUID part into first letter, last letter, and whatever is in the middle.

print Id="82b8be2d-dfa7-4bd1-8f63-24ad26d31449"
| extend guid_bytes = extract_all(@"(\w)(\w+)(\w)", Id)
ID guid_bytes
82b8be2d-dfa7-4bd1-8f63-24ad26d31449 [["8","2b8be2","d"],["d","fa","7"],["4","bd","1"],["8","f6","3"],["2","4ad26d3144","9"]]

Extract a subset of capture groups

Shows how to select a subset of capturing groups. The regular expression matches the first letter, last letter, and all the rest. The captureGroups parameter is used to select only the first and the last parts.

print Id="82b8be2d-dfa7-4bd1-8f63-24ad26d31449"
| extend guid_bytes = extract_all(@"(\w)(\w+)(\w)", dynamic([1,3]), Id) 
ID guid_bytes
82b8be2d-dfa7-4bd1-8f63-24ad26d31449 [["8","d"],["d","7"],["4","1"],["8","3"],["2","9"]]

Using named capture groups

You can use named capture groups of RE2 in extract_all(). The captureGroups uses both capture group indexes and named capture group reference to fetch matching values.

print Id="82b8be2d-dfa7-4bd1-8f63-24ad26d31449"
| extend guid_bytes = extract_all(@"(?P<first>\w)(?P<middle>\w+)(?P<last>\w)", dynamic(['first',2,'last']), Id) 
ID guid_bytes
82b8be2d-dfa7-4bd1-8f63-24ad26d31449 [["8","2b8be2","d"],["d","fa","7"],["4","bd","1"],["8","f6","3"],["2","4ad26d3144","9"]]