add class via jquery but only when not exists

Question

I would like to add a class (class=\"bbox\") to a ul-list but only if no class exists. This is what i have so far. How do I check with jquery if a class exists in the ul-tag

Answer 1

If I'm toggling between 2 classes I use this method

if (foo)
    $('button.btn-foo').removeClass('foo bar').addClass('foo');
if (bar)
    $('button.btn-foo').removeClass('foo bar').addClass('bar');

So I don't have to check the current setting of the button

Answer 2

If you want to check if a specific class exists then:

 if(!$("ul").hasClass("class-name")){
    $("ul").addClass("bbox");
 }

If you want to check if any class exists:

if ($('ul').attr('class') == '') {
    $("ul").addClass("bbox");
}

Answer 3

you can use this code for adding class only when if not exist

$('.your-dom:not(.class-name)').addClass('class-name');

Answer 4

Just use $('.selector').addClass("myClass");.

The jQuery add/remove class functions both check for duplicates internally, meaning that calling addClass twice only will add the class once.

Answer 5

I was wondering this would work fine -->

$("ul").removeClass("bbox").addClass("bbox");

First it will remove if there is any and then add new one . Worked best for me as i am too lazy to type all that if thingy.

Answer 6

Concisely:

// fine, because nothing happens if 
// there are no matching elements
$("ul[class='']").addClass("bbox");