getOptionalNamedGroup

Reads an optional named capture group from a regex match, distinguishing an absent group from a present empty one.

Returns the captured string when the group participated in the match — which may be '' for a zero-width match such as \w* — or null when the group, or the match’s groups object, is absent (e.g. an optional (?:…)? group that did not match). Because null is returned only for a genuinely-absent group, a caller’s ?? <default> is a live branch rather than the dead one that match.groups?.[name] ?? '' leaves for a mandatory group. For a group that must always be present, use getMandatoryNamedGroup.

Import:

import { getOptionalNamedGroup } from 'obsidian-dev-utils/reg-exp';

Signature:

function getOptionalNamedGroup(match: RegExpMatchArray, groupName: string): string | null

Parameters:

Parameter	Type	Description
match	RegExpMatchArray	The match returned by RegExp.exec, String.matchAll, or String.match.
groupName	string	The name of the capture group to read.

Returns: string | null — The captured string, or null when the group is absent.

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Links to this page:

• getMandatoryNamedGroup