How to flatten a multi-dimensional array in JavaScript

Coming from Python which is considered to be the data-science language I'm very pleased with JavaScript's data-crunching functions. They are just succinct and neat!

Take the one for example, here's how you flatten a two-dimensional array:

const nestedArray = [['👍', '🐍'], ['👎', '🐘'], ['👏', '➡']];
const flatArray = [].concat(...nestedArray); 
console.log(flatArray) // [ '👍', '🐍', '👎', '🐘', '👏', '➡' ]