How can I perform a RegEx match in Twig?

Question

Is it possible to perform a RegEx match on a string in Twig?

I'm looking for something like this:

{% set string = "This is **string**. **wer**  qewr **234**" %}
{% set match  = string.matches(/([*][*])(.*)([*][*])/g) %}

Answer 1

Currently Twig uses regular expressions only with Comparisons:

{% if string matches '{^[\d\.]+$}' %}
    Do Stuff
{% endif %}

Craft itself currently doesn't have any custom Twig filters or functions either.

But there are third-party plugins which might help you:

• Twig PCRE Filters
• Low Regex

Answer 2

This works for me just fine:

{# Removes all characters other than numbers and + #}
{{ profile.phone|replace('/[^0-9+]/', '') }}

Answer 3

Answers for 2023 using Craft CMS 4

For simple find and replace: you can just use the replace filter, it accepts RegEx now.

For more complicated lookups: If you're looking to just add Craft CMS filters in general or use PHP filters, like preg_match_all() you can install the Twig Toolbox plugin, create the file config/twig-toolbox.php with the following code to enable the filter or add more as needed:

<?php return [
    'filters' => [
        'preg_match_all' => function(string $subject, string $pattern): array {
            preg_match_all($pattern, $subject, $matches, PREG_SET_ORDER);
            return $matches;
        },
    ],
    'functions' => [],
    'globals' => [],
    'tests' => [],
];

Please note, the above filter is a basic version of the actual preg_match_all, see the full documentation and adapt as you see fit.