Quick Reference
The Element querySelectorAll() method returns an element’s child elements, as a static NodeList object, that match specified CSS selectors.
<div id="my_div">
<h2 class="example">My heading</h2>
<p class="example">My paragraph.</p>
</div>
<button onclick="my_function()">Choose the heading</button>// function called by the button above
function my_function() {
let x = document.getElementById('my_div').querySelectorAll('.example');
x[0].style.backgroundColor = '#ff0000';
}Output
(no output; but the H2 header has its background changed to red)Syntax
element.querySelectorAll(CSS selectors separated by commas)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.