(PHP 7) Check if code point is a digit character

(PHP 5, PHP 7) Composes a MIME header field

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

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

(PHP 5.5.0, PHP 7, PECL >= 3.0.0a1) Get last error message on the object

(PHP 5 >= 5.3.0, PHP 7, PECL intl >= 1.0.0) Sets the calendar type used by the formatter

(PHP 5 >= 5.3.0, PHP 7, PECL intl >= 1.0.0) Set a symbol value

(PHP 5 >= 5.3.0, PHP 7, PECL intl >= 1.0.0) Returns a key-value array of locale ID subtag elements.

(PHP 5 >= 5.3.0, PHP 7, PECL enchant >= 0.1.0 ) create a new dictionary using a tag

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