(PHP 5 >= 5.4.0, PHP 7) Checks if the trait exists

(No version information available, might only be in Git) This method updates an entry in the hash with a new

(PHP 7) Checks if it is a built-in type public

(PHP 4, PHP 5, PHP 7) Count all elements in an array, or something in an object

(PHP 4, PHP 5, PHP 7) Get the default properties of the class

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Computes the difference of arrays with additional index check

(PHP 4, PHP 5, PHP 7) Sort an array with a user-defined comparison function and maintain index association

(PHP 5 >= 5.1.0, PHP 7) Gets the property doc comment

(PHP 4, PHP 5, PHP 7) Finds whether a variable is a number or a numeric string

(PECL classkit >= 0.1) Dynamically removes the given method