There is an exception when working with
attributes - this is the attribute
class
.
This word is special in JavaScript and
therefore we cannot simply write
elem.class
to read the value of
the class
attribute. Instead,
write elem.className
.
Let's look at an example. Let's say we have this input:
<input id="elem" class="aaa bbb">
Let's output the value of the class
attribute for our input:
let elem = document.querySelector('#elem');
console.log(elem.className); // shows 'aaa bbb'
There are other exceptions, such as
the for
attribute. It should
be accessed via htmlFor
.
A div is given:
<div id="elem" class="content no-gap"></div>
There is also a button. By clicking on
the button, read and display the value
of the class
attribute of our div.
A div is given:
<div id="elem"></div>
There is also a button. By pressing the
button, write some class into the
class
attribute of our div.
Given a div with several CSS classes separated by spaces:
<div id="elem" class="aaa bbb ccc"></div>
There is also a button. On button click, get an array of CSS classes of our div.