(PHP 4 >= 4.0.4, PHP 5, PHP 7) Check for alphabetic character(s)

(PHP 4, PHP 5, PHP 7) Checks if the object has this class as one of its parents or implements it.

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Get float value of a variable

(PHP 4, PHP 5, PHP 7) Get string value of a variable

(PHP 4, PHP 5, PHP 7) Unset a given variable

(No version information available, might only be in Git) This factory method creates a hash from a file

(PHP 5, PHP 7) Apply a user function recursively to every member of an array

(PHP 4, PHP 5, PHP 7) Determine if a variable is set and is not NULL

(PHP 4 >= 4.0.3, PHP 5, PHP 7) De-register a function for execution on each tick

(PHP 5, PHP 7) Returns an array of all declared interfaces