(PHP 4 >= 4.3.0, PHP 5, PHP 7) Count the number of substring occurrences

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Encode character to HTML numeric string reference

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Perform case folding on a string

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Set start point of next regular expression match

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Parse GET/POST/COOKIE data and set global variable

(PHP 5 >= 5.4.1, PHP 7) Perform a regular expresssion seach and replace with multibyte support using a callback

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Multibyte regular expression match for predefined multibyte string

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Detect HTTP input character encoding

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Setup string and regular expression for a multibyte regular expression match

(PHP 5, PHP 7) Returns an array of all supported encodings