Function (programming): Difference between revisions

Content deleted Content added

Inline

Revision as of 15:28, 28 March 2004

@@ Line 1: / Line 1: @@
+#REDIRCT [[subroutine]]
-In computer programming, a '''function''' is a [[subroutine]] which can be called with a set of [[parameter]]s and which is defined or declared as though it always returns a value, sometimes using a special symbol to indicate that no value is ever actually returned. For example, in the [[C programming language|C]] and [[Java programming language]]s, a function that never returns a value would be defined as though the returned value was of type ''void''.  The only difference between a void function and a [[procedure]] is terminological.
-If a function can in fact return a value, then the function may be referenced within an [[expression]], in which case if a value is returned, it is used in the natural way in the evaluation of the expression.
-For example, in the C programming language, in which 'int' signifies a sufficiently small integer, if f and g are declared as follows:
- int f(int a);
- int g(int a);
-and if f(1) returns 1, and if g(2) returns 2, then the expression ''f(1) + f(2)''
-would evaluate to 3.
-In [[procedural programming language]]s, functions may have [[side-effects]], that is to say, they may have outside inputs and outputs.  This makes them not equivalent to [[function (mathematics)|mathematical functions]].