Determining whether jQuery has not found any element
JqueryCss SelectorsJquery Problem Overview
I'm using jQuery's selectors, especially id selector:
$("#elementId")...
How should I determine whether jQuery has found the element or not?
Even If the element with the specified id doesn't exist the next statement give me: [object Object]
alert($("#idThatDoesnotexist"));
Jquery Solutions
Solution 1 - Jquery
$('#idThatDoesnotexist').length
is what you're looking for. (If it finds nothing, this will === 0
.) So your conditional statement should probably be:
if($('#id').length) { /* code if found / } else { / code if not found */ }You're getting an object returned from that alert because jQuery (almost) always returns the "jQuery object" when you use it, which is a wrapper for the elements jQuery's found that permits method chaining.
Solution 2 - Jquery
Futuraprime is right but you can shorten your syntax by doing the following:
if ($("#id").length) {
//at least one element was found
} else {
//no elements found
}
Solution 3 - Jquery
!$.isEmptyObject($.find('#id'))
This will return true if the element exists and false if it doesn't.
Solution 4 - Jquery
$('#my_selector').length > 0
$('#my_selector').get(0) !== undefined
$('#my_selector')[0] !== undefined
This is the basic, now do whatever you want.