First class functions are a common feature of [FunctionalLanguages]. In this family of languages, functions can be passed to a function and returned as values of a function, just like any other standard values (numbers, strings, etc). This feature allows for more elegant programming.
For example, in OcamlLanguage :
(* Define a function which takes an integer x and multiplies it by n *) let times_n n = function x -> x * n ;; (* Define functions twice and thrice that multiply their input *) (* by 2 and 3 respectively. *) (* These functions are values of the times_n function. *) let twice = times_n 2;; let thrice = times_n 3;; (* Let's try these functions *) twice 3;; - : int = 6 thrice 3;; - : int = 9