(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) Sort an array with a user-defined comparison function and maintain index association

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

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Split an array into chunks

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Calculate the sum of values in an array

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

(PHP 4, PHP 5, PHP 7) Return the current element in an array

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

(PHP 5 >= 5.2.0, PHP 7) Fill an array with values, specifying keys

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