DOM

Element Contains

This snippet checks whether the parent element contains the child.

function elementContains(parent, child) {
  return parent !== child && parent.contains(child);
}

Example

const head = document.querySelector("head");
const body = document.querySelector("body");

elementContains(head, body); // true

Has Class

This snippet checks whether an element has a particular class.

const hasClass = (el, className) => el.classList.contains(className);

Example

hasClass(document.querySelector("p"), "some-class"); // true