mdn js element.queryselector code example
Example 1: javascript queryselector
//Pretend there is a <p> with class "example"
const myParagraph = document.querySelector('.example');
//You can do many this with is
myParagraph.textContent = 'This is my new text';
Example 2: document.queryselector
<div id="foo\bar"></div>
<div id="foo:bar"></div>
<script>
console.log('#foo\bar');
document.querySelector('#foo\bar');
console.log('#foo\\bar');
console.log('#foo\\\\bar');
document.querySelector('#foo\\\\bar');
document.querySelector('#foo:bar');
document.querySelector('#foo\\:bar');
</script>