Function (computer programming)

In <a href="/facts/Computer_programming/QmSsFnu0">computer programming</a>, a function (also procedure, method, subroutine, routine, or subprogram) is a callable unit of <a href="/facts/Software_logic/fnl5NmRt">software logic</a> that has a well-defined <a href="/facts/Interface_(computing)/zdfp8unT">interface</a> and <a href="/facts/Behavior/0Y1VqmVX">behavior</a> and can be invoked multiple times.
Callable units provide a powerful programming tool. The primary purpose is to allow for the decomposition of a large and/or complicated problem into chunks that have relatively low <a href="/facts/Cognitive_load/MAAlVLBs">cognitive load</a> and to assign the chunks meaningful names (unless they are anonymous). Judicious application can reduce the cost of developing and maintaining software, while increasing its quality and reliability.
Callable units are present at multiple levels of <a href="/facts/Abstraction/p7l9eHGd">abstraction</a> in the programming environment. For example, a <a href="/facts/Programmer/WGTS1Jv9">programmer</a> may write a function in <a href="/facts/Source_code/o9J6Jv23">source code</a> that is compiled to <a href="/facts/Machine_code/bgdQ1Fxf">machine code</a> that implements similar <a href="/facts/Semantics/1L4WwLAP">semantics</a>. There is a callable unit in the source code and an associated one in the machine code, but they are different kinds of callable units – with different implications and features.

Function (computer programming) open-in-new

Function (computer programming)