(PHP 4, PHP 5, PHP 7) Perform a global regular expression match

(PHP 7) Perform a regular expression search and replace using callbacks

(PHP 4, PHP 5, PHP 7) Perform a regular expression match

(PHP 5 >= 5.2.0, PHP 7) Returns the error code of the last PCRE regex execution

(PHP 4, PHP 5, PHP 7) Return array entries that match the pattern

(PHP 4, PHP 5, PHP 7) Perform a regular expression search and replace

(PHP 4 >= 4.0.5, PHP 5, PHP 7) Perform a regular expression search and replace using a callback

Examples: Use of this modifier is discouraged, as it can easily introduce security vulnerabilites:

(PHP 4, PHP 5, PHP 7) Split string by a regular expression