Solved

Difference between recursion and iteration - JavaScript

Posted on 2011-09-11
7
331 Views
Last Modified: 2012-06-27
Hi,

Can you please provide me a simple example on:

Difference between recursion and iteration - JavaScript

Thanks
0
Comment
Question by:milani_lucie
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
7 Comments
 
LVL 40

Assisted Solution

by:gurvinder372
gurvinder372 earned 125 total points
ID: 36520714
0
 
LVL 82

Accepted Solution

by:
leakim971 earned 125 total points
ID: 36520738
Test page (recursion) : http://jsfiddle.net/Mjzkk/
function factorial_recursion(n) {
      if(n!=1) n * factorial_recursion;
}

Open in new window


test page (iteration) : http://jsfiddle.net/Kvmrc/
function factorial_iteration(n) {
    a = n;
    while(n!=1) {
        n = n -1;
        a *= n;
    }
    return a;
}

Open in new window


http://en.wikipedia.org/wiki/Factorial
0
 
LVL 82

Expert Comment

by:leakim971
ID: 36520739
correction (recursion) :
function factorial_recursion(n) {
    if(n!=1) n = n * factorial_recursion(n-1);
    return n;
}

Open in new window

0
PeopleSoft Has Never Been Easier

PeopleSoft Adoption Made Smooth & Simple!

On-The-Job Training Is made Intuitive & Easy With WalkMe's On-Screen Guidance Tool.  Claim Your Free WalkMe Account Now

 
LVL 82

Expert Comment

by:leakim971
ID: 36520742
to be mathematicaly correct (and not just for the example) : 0! = 1
so :

function factorial_recursion(n) {
      if(n==0) return 1;
      if(n!=1) n * factorial_recursion(n-1);
      return n;
}

Open in new window

and :
function factorial_iteration(n) {
    if(n==0) return 1;
    a = n;
    while(n!=1) {
        n = n -1;
        a *= n;
    }
    return a;
}

Open in new window

0
 
LVL 17

Assisted Solution

by:sonawanekiran
sonawanekiran earned 125 total points
ID: 36520837
Recursion repeatedly invokes the mechanism itself as explained by @leakim971 using factorial number. Both iteration and recursion are based on a control structure. Iteration explicitly uses a repetition structure; recursion achieves repetition through repeated method calls.

Keep in Mind:

Recursion consequently the overhead of method calls. This can be expensive in both processor time and memory space.
0
 
LVL 9

Assisted Solution

by:user_n
user_n earned 125 total points
ID: 36524822
Recursion invokes the function itself. If you do not stop the process right it might proceed forever. It takes more space in the stack of the computer (http://en.wikipedia.org/wiki/Call_stack), because of witch it usually takes more time and memory.But in some cases it is the easiest way of finding of programing solution to a problem. Some more info (http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-046j-introduction-to-algorithms-sma-5503-fall-2005/video-lectures/)
0

Featured Post

MS Dynamics Made Instantly Simpler

Make Your Microsoft Dynamics Investment Count  & Drastically Decrease Training Time by Providing Intuitive Step-By-Step WalkThru Tutorials.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Having worked on larger scale sites, we found out that you are bound to look at more scalable solutions to integrating widgets, code snippets or complete applications and mesh them into functional sites, in any given composition. To share some of…
This article discusses how to create an extensible mechanism for linked drop downs.
The viewer will learn the basics of jQuery, including how to invoke it on a web page. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery.: (CODE)
The viewer will learn the basics of jQuery including how to code hide show and toggles. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery…

690 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question