Solved

Difference between recursion and iteration - JavaScript

Posted on 2011-09-11
7
313 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
7 Comments
 
LVL 40

Assisted Solution

by:gurvinder372
gurvinder372 earned 125 total points
Comment Utility
0
 
LVL 82

Accepted Solution

by:
leakim971 earned 125 total points
Comment Utility
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
Comment Utility
correction (recursion) :
function factorial_recursion(n) {
    if(n!=1) n = n * factorial_recursion(n-1);
    return n;
}

Open in new window

0
How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

 
LVL 82

Expert Comment

by:leakim971
Comment Utility
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
Comment Utility
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

Expert Comment

by:user_n
Comment Utility
0
 
LVL 9

Assisted Solution

by:user_n
user_n earned 125 total points
Comment Utility
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

IT, Stop Being Called Into Every Meeting

Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

Join & Write a Comment

When you need to keep track of a simple list of numbers or strings, the Array object is your most direct tool.  As we saw in my earlier EE Article (http://www.experts-exchange.com/A_3488.html), typical array handling might look like this: (CODE) B…
I've been trying to accomplish this for a while and it just struck me yesterday how to accomplish this task. I have done searches all over the internet looking for ways to email pages from my applications and finally I have done it!!! Every single s…
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…

728 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

Need Help in Real-Time?

Connect with top rated Experts

15 Experts available now in Live!

Get 1:1 Help Now