why is .querySelector not picking up class code example

Example 1: queryselector name attribute

document.querySelectorAll('[property]'); // All with attribute named "property"
document.querySelectorAll('[property="value"]'); // All with "property" set to "value" exactly.

Example 2: 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';