Checking elements in JavaScript

Given an element:

<div id="elem" class="www"></div>

Check if this element is an element with www class.

Given an element. Check if this element is a paragraph.

Given two variables elem1 and elem2 containing two elements:

<div id="elem1">
	<p id="elem2"></p>
</div>

let elem1 = document.querySelector('#elem1');
let elem2 = document.querySelector('#elem2');

Check if an element from elem2 is a child of an element from elem1.