(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 4, PHP 5, PHP 7) Prepend one or more elements to the beginning of an array

(PHP 4 >= 4.0.1, PHP 5, PHP 7) Removes duplicate values from an array

(PHP 5 >= 5.5.0, PHP 7) Return the values from a single column in the input array

(PHP 4 >= 4.0.5, PHP 5, PHP 7) Searches the array for a given value and returns the corresponding key if

(PHP 4, PHP 5, PHP 7) Shift an element off the beginning of array

(PHP 4, PHP 5, PHP 7) Return all the values of an array

(PHP 5 >= 5.1.0, PHP 7) Computes the difference of arrays using a callback function on the keys for comparison

(PHP 4, PHP 5, PHP 7) Fetch a key from an array