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

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

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Replace regular expression with multibyte support

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Send encoded mail

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Find position of last occurrence of a string in a string

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

(PHP 5 >= 5.2.0, PHP 7) Finds first occurrence of a string within another

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

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

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