Over a million developers have joined DZone.
{{announcement.body}}
{{announcement.title}}

PHP: preg_match Give Names to the Matches

DZone's Guide to

PHP: preg_match Give Names to the Matches

· Web Dev Zone ·
Free Resource

Jumpstart your Angular applications with Indigo.Design, a unified platform for visual design, UX prototyping, code generation, and app development.

So Called – Subpatterns

In PHP 5.2.2+ you can name the sub patterns returned from preg_match with a specific syntax.

Named subpatterns now accept the syntax (?<name>) and (?’name’) as well as (?P<name>). Previous versions accepted only (?P<name>)

This is extremely helpful, when dealing with long patterns. As you may know you can simply use the “old school” way and to call the matches by their number based index:

    $haystack = '01 Jan 1970';
$pattern = '/(\d{1,2})\ (Jan|Feb)\ (19\d\d)/';

preg_match($pattern, $haystack, $matches);

print_r($matches);

Although it may look difficult to maintain, now you can simply name the sub patterns of preg_match and to call them with their associative array keys. This is more clear when writing code and it’s definitely more maintainable.

    $haystack = '01 Jan 1970';
$pattern = '/(?<day>\d{1,2})\ (?<month>Jan|Feb)\ (?<year>19\d\d)/';

preg_match($pattern, $haystack, $matches);

print_r($matches);

// now there's $matches['day'], $matches['month'] ...

Take a look at the Indigo.Design sample applications to learn more about how apps are created with design to code software.

Topics:

Published at DZone with permission of

Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}