Quick Reference
The DOMTokenList keys() method returns an iterator with the keys from a DOMTokenList, which is a set of space-separated tokens that can be accessed by index.
<!-- html element to place output -->
<p id="my_output" class="class1 class2 class3"></p>// variables
let my_list = document.getElementById('my_output').classList;
let my_text = '';
// loop through the tokens
for (let x of my_list.keys()) {
my_text += x + '<br>';
}
// output to the HTML element
document.getElementById('my_output').innerHTML = my_text;Output
0
1
2Note
Arrays count starting from zero NOT one. So item 1 is position [0], item 2 is position [1], and item 3 is position [2] … and so on.
Syntax
domtokenlist.keys()JavaScript Notes:
- When using JavaScript, single or double quotation marks are acceptable and work identically to one another; choose whichever you prefer, and stay consistent
- JavaScript is a case-sensitive language; firstName is NOT the same as firstname
- Arrays count starting from zero NOT one; so item 1 is position [0], item 2 is position [1], and item 3 is position [2] … and so on
- JavaScript variables must begin with a letter, $, or _
- JavaScript variables are case sensitive (x is not the same as X)
We’d like to acknowledge that we learned a great deal of our coding from W3Schools and TutorialsPoint, borrowing heavily from their teaching process and excellent code examples. We highly recommend both sites to deepen your experience, and further your coding journey. We’re just hitting the basics here at 1SMARTchicken.