if else statement issue

[noahgelman]

I want to write an if else statement in just javascript, no jquery. I want the condition to be whether a specific element has a certain class or not, how can I do this?

[Bob]

I don’t think you can do it with plain Javascript and you would nee jquery for this. Javascript hasn’t got a function to get elements by their class as far as I know.

It does however has getElementById, so you can select elements based on a specific ID.

Why don’t you want to use jquery?

[mdgrech]

var element = get.YourElement

if (element.hasClass(‘foo’)) { do.something }

[noahgelman]

@bob, thanks. It’s weird that javascript doesn’t have a function to get elements by class, or at least detect whether an element has a certain class or not. I didn’t want to use jquery because the rest of the related scripts are pure javascript and I didn’t want any issues with it having to wait to load jquery before the scripts could run properly. I dont think I’ll have any of those troubles though, it seems to be working just fine with mdgrech’s suggestion.

@mdgrech, thank you too. that was the same solution I came up with as well. Unfortunately it uses jQuery’s .hasClass() but its fine, win some lose some.

[TT_Mark]

@Bob, sorry but if JavaScript cannot do it then how the hell do you think JQuery can?

@noahgelman I believe you can do the following:

if ( document.getElementById("test").getAttribute("class") == 'class')

I haven’t tested this though!

[noahgelman]

Yup, that worked perfectly. I’m used to using jQuery for all my problems. My javascript isn’t up to snuff. jQuery isn’t option on the current project so I’m really learning a lot of javascript

[Bob]

@TT_Mark, does Javascript has a function to get elements by their class then? And I don’t mean the way you posted it above, but something like getElementByClass. I don’t think it does, hence I posted that.

[Bob]

I know, but what I meant is there is no function in Javascript as far as I know that can get elements by their class directly, only indirectly via the example TT_Mark gave. Or can Javascript do it directly? Thats all I said really..

[TT_Mark]

Noah never asked for a function that checked if the element had a certain class, he simply asked for the code to do it without using JQuery and your response was that it couldn’t be done without JQuery.

I was simply pointing out that JQuery is nothing more than JavaScript simplified. I assume the JQuery .hasClass() function is built on top of the code I posted above

[Chris Coyier]

var test = document.getElementById('test');

var class = test.className;



if (class == 'thing') {

// yeah buddy

} else {

// nope darling

}

Remember that classes can be space-separated though, so you’d likely need to split them into an array based on spaces and then loop through that array testing each one.

[noahgelman]

But in jQuery, you can select all classes on the page like this: $(‘.class’).dosomething(). I think Bob was talking about a javascript equivalent to that.

[Rob MacKay]

That’s why jQuery is pure awesome. :)

[noahgelman]

So there’s no easy way to do that in javascript is there? :(

[Chris Coyier]

Well there is: https://developer.mozilla.org/en/DOM/document.getElementsByClassName

It’s just not supported in all browsers. So… there are little scripts that use to simulate it. http://snook.ca/archives/javascript/your_favourite_1

[noahgelman]

This turned into more of an interesting topic than I expected.

.getElementsByClassName(names) works in firefox obviously. What versions of Chrome, Safari, Opera, and IE support it, if they do?

[Author]

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