Quick Reference
The Element id property sets or returns the value of an element’s id attribute.
<button id="my_button" onclick="change_id()">Change ID</button>
<!-- output to the HTML element -->
<p id="my_output"></p>
Get ID:
// variable
let my_id = document.getElementsByTagName('p')[0].id;
// output to the HTML element
document.getElementById('my_output').innerHTML = my_id;
Set ID:
// function called by the button click
function change_id() {
element.id = 'my_new_id';
getID();
}
let element = document.getElementById('my_button');
getID();
Output
Get ID:
my_output
Set ID:
(no output; the button ID is set to my_new_id)
Syntax
Get ID:
element.id
Set ID:
element.id = new_id
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.