(PHP 4, PHP 5, PHP 7) Split a string into smaller chunks

(PHP 4, PHP 5, PHP 7) Convert binary data into hexadecimal representation

(PHP 4, PHP 5, PHP 7) Replace all occurrences of the search string with the replacement string

(PHP 4 >= 4.0.2, PHP 5, PHP 7) Binary safe case-insensitive string comparison of the first n characters

(PHP 4, PHP 5, PHP 7) Un-quote string quoted with

(PHP 4 >= 4.1.0, PHP 5, PHP 7) Query language and locale information

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Convert all HTML entities to their applicable characters

(PHP 4 >= 4.0.1, PHP 5, PHP 7) Calculate Levenshtein distance between two strings