Mastering Windows PowerShell Scripting - Third Edition

Non-capturing groups

By default, every group is a capture group. A group can be marked as non-capturing by using ?: before the expression. In the following example, the third group has been marked as a non-capturing group:

PS> 'first second third' -match '(?<One>first) (?<Two>second) (?:third)'TruePS> $matchesName Value---- -----Two secondOne first0 first second third

The outer group, which previously added second third to the matches list, is now excluded from the results:

PS> 'first second third' -match '(first) (?:(second) (third))'; $matchesTruePS> $matchesName                           Value----                           -----3                              third2                              second1                              first0                              first second third

This technique may be useful when using -replace—it simplifies the list of tokens available, even if an expression grows ...