Finds the first descendant element of this document that matches the specified group of selectors.
Finds the first descendant element of this document that matches the specified group of selectors.
Unless your webpage contains multiple documents, the top-level querySelector method behaves the same as this method, so you should use it instead to save typing a few characters.
selectors should be a string using CSS selector syntax.
var element1 = document.querySelector('.className');
var element2 = document.querySelector('#id');
For details about CSS selector syntax, see the CSS selector specification.