<p>{{stub}}
====== Recursion ======</p>

<p>=====  Introduction  =====
The term <strong>Recursion</strong> describes processes or structures which are defined or described in terms of themselves.</p>

<p>In programming, a procedure or function is said to be //recursive// if it calls itself.</p>

<p>=====  Code Examples  =====</p>

<p><code>
 integer function factorial ( integer n ) 
 {
    if( n == 0 )
    {
        return( 1 )
    }
    else
    {
        return( factorial( n - 1 ) ) 
    }
 }
</code></p>

<p>Another example is a binary search or searching data in a tree structure.
<code>
Node findNode( Node curNode, string key ) {
    if( curNode.key == key ) {
        return curNode;
    }
    foreach( Node n in curNode.nodes[[]] ) {
        Node ret = findNode( n, key );
        if( ret != null ) {
            return ret;
        }
    }
    return null;
}</p>

<p>=====  Using Recursion  =====</p>

<p>Why use recursion?  When should I use it in programming?</p>

<p>====  Pros and Cons  ====</p>

<p>=====  Examples of Recursion  =====</p>

<p>===  Recursive Definitions  ===
For example, in spoken language, a phrase is be made up of a collection of individual words and smaller phrases. This is a recursive definition, because a phrase can consist of phrases.</p>

<p>===  Recursive Algorithms  ===
In mathematics, the factorial of a number, N, can be expressed as the product of N with the factorial of N-1, unless N = 0, in which case the factorial is 1.</p>

<p>=====  References  =====
[[http://www.amazon.co.uk/Godel-Escher-Bach-Eternal-anniversary/dp/0140289208/|Godel, Escher, Bach: An Eternal Golden Braid]]</p>

<p>=====  See Also  =====
[[Iteration]]</p>