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JavaScript

Posted by Łukasz Czuliński
Łukasz Czuliński
8,646 Points

Functions working when nodes found by getElementById, but not getElementsByClassName

I'm stumped as to why this behavior is happening. For example, everything works great when I do:

document.getElementById('quote-form').onmouseover = function(){
    console.log('the function');
};

But when I change it to :

document.getElementsByClassName('form').onmouseover = function(){
    console.log('the function');
};

I get nothing. My form is as follows:

<form method="POST" action="http://localhost:8000/quotes" accept-charset="UTF-8" class="form" id="quote-form">

Any ideas what's happening here?

1 Answer

Hugo Paz
Hugo Paz
15,622 Points

Hi lukasz,

The .getElementsByClassName() method returns an array-like object of all child elements which have all of the given class names.

So you need to specify which object you want to trigger the .onmouseover.

Assuming the form is the first element with that class, you just need to use this code:

document.getElementsByClassName('form')[0].onmouseover = function(){
    console.log('the function');
};
Łukasz Czuliński
Łukasz Czuliński
8,646 Points

Brilliant, thanks! Makes perfect sense.