Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

how to check for existing element before loading variable

Posted on 2011-03-18
2
Medium Priority
?
363 Views
Last Modified: 2012-05-11
Attached code. This works, but there are circumstances where the "selectprogram" radio button may not exist on the page (or there could be many with that name). In that case, my function fails, I believe because this becomes invalid:

var inputVal = $("#mainform input[name='selectprogram']:checked").val();

If there is no element with the name "selectprogram" then I want to do this:

document.mainform.submit();

This is possible? Do I just need to add another conditional statement? Thank you!
function setprogram(displaycat,task){
	document.mainform.displaycat.value=displaycat;
	document.mainform.task.value=task;

	var inputVal = $("#mainform input[name='selectprogram']:checked").val();

	if (undefined==inputVal){
		if ($('#saveandviewbutton').attr("disabled")==true) {
			$('#workoutalert').fadeIn();
		}
	} else {
		document.mainform.submit();
	}
}

Open in new window

0
Comment
Question by:bbdesign
[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
2 Comments
 
LVL 82

Accepted Solution

by:
leakim971 earned 2000 total points
ID: 35168933
$("#mainform input[name='selectprogram']:checked").length return the number of object found.

var $selection = $("#mainform input[name='selectprogram']:checked");
if( $select.length == 1) {
// only one found, phew !!!
}
else if( $select.length >=1 ) {
// more than one found !!!!
}
else {
// ok submit !!
 document.mainform.submit();
}

Open in new window

0
 

Author Comment

by:bbdesign
ID: 35183777
.length -- great! Easy, too. Thanks.
0

Featured Post

Hire Technology Freelancers with Gigs

Work with freelancers specializing in everything from database administration to programming, who have proven themselves as experts in their field. Hire the best, collaborate easily, pay securely, and get projects done right.

Question has a verified solution.

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

PROBLEM: The other day I was working on adding an ajax request to a webpage that already had a dialog box on the page.  The dialog box was using relative positioning to be positioned next to a form field I had on the page.  Everything was working…
Introduction JSON is an acronym for JavaScript Object Notation.  It is a text-string data transport mechanism, capable of representing simple or complex data structures in a consistent and easy-to-read manner.  Similar in concept to XML, but more e…
The viewer will learn how to dynamically set the form action using jQuery.
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…
Suggested Courses

715 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