#REGEX CAPTURE GROUP PORTABLE#

The / character is the delimiter.įorward slashes ( /) are frequently used as the delimiter, but it can be any character such as ~, !, #, $, etc. In the example above, (foo|bar) is the expression itself, and i is a flag/modifier.

In any regular expression, a delimiter character contains the expression, followed by optional flags. The regular expression is contained within two characters, followed by optional flags.Ĭonsider the regular expression below: /(foo|bar)/i For example, named captures are supported even in older PHP versions, but in JavaScript, named captures feature was only added in ECMAScript 2018.Įach and every regular expression has two parts: the expression, and flags.

#REGEX CAPTURE GROUP PORTABLE#

Further, using these improvements also means the regular expressions might be less portable to other languages. Note that they might not work in older PHP versions (older than PHP 7.3). Here are some tips to improve and write better regular expressions in PHP. However, writing a self-explanatory and more readable regular expressions in the first place can help in the long run. IDEs can provide nicer syntax highlighting to help make a given regular expression more readable and easier to grasp and even offer quick-fixes to improve them. PHP's filters and ctype functions provide validations such as URL, email, and alphanumeric values, that helps to not use a regular expressions in the first place. PHP uses PCRE ( PCRE2 since PHP 7.3) regular expression flavor, and it comes with several advanced features that can help write readable, self-explanatory, and easy to maintain regular expressions. Regular Expressions are powerful, PHP but they are not known to be readable, and more often than not, maintaining a regular expression is not a straight-forward task.

Regex capture group