for jquery is there any error thrown when manipulating a dom element that doesnt exist

Question

In my code I'm not checking if a DOM element exists before I manipulate it and jquery does not seem to throw any errors, even if it doesn't exist.

$('.test').addClass('hide');

where the test class doesn't exist, but this doesn't throw any errors.

So is this expected? should I be checking if it exists first?

This is expected behaviour. jQuery will not error when calling a method on a jQuery object which is empty. — Rory McCrossan, Feb 20 '20 at 15:03
This time it gets empty array and loops via it, so no error thrown. But if you try to get JS object, then it can throw error, e.g. `$('.tests')[0].value` — Justinas, Feb 20 '20 at 15:04
Okay got it, so no need to check if it exists first for jquery? — Tenzin Choklang, Feb 20 '20 at 15:15
the link you shared is explain the speed difference between the two, saying that wrapping it in a if condition is better, i am asking in terms of errors if there is a difference. And the answer is no — Tenzin Choklang, Feb 20 '20 at 16:39

score 0 · Answer 1 · answered Feb 20 '20 at 15:07

0

You can use:

if ($('.test').length) {
   // do stuff
}

With JS only:

document.querySelector('non existing') // => null

answered Feb 20 '20 at 15:07

Constantin

You could do this, but in jQuery it's a waste of time: https://stackoverflow.com/a/21989907/519413 – Rory McCrossan Feb 20 '20 at 15:09
Agree. I just answered the question on how to test whether an element exists. – Constantin Feb 20 '20 at 15:23
@Constantin in which case you would direct OP to https://stackoverflow.com/questions/31044/is-there-an-exists-function-for-jquery :) – freedomn-m Feb 20 '20 at 16:09

1 Answers1