const smile = "😀";

smile.length; // => 2

const smile = "\uD83D\uDE00";

smile === "😀"; // => true
smile.length; // => 2

const message = "Hello!";
const smile = "😀";

[...message].length; // => 6
[...smile].length; // => 1

height
parent’s height
width
parent’s width
top
parent’s height
left
parent’s width
margin-top
parent’s width
margin-left
parent’s width
padding-top
parent’s width
padding-left
parent’s width
translate-top
self’s height
translate-left
self’s width