30-seconds-of-code/snippets/deepClone.md

deepClone

Creates a deep clone of an object.

Use recursion. Use Object.assign() and an empty object ({}) to create a shallow clone of the original. Use Object.keys() and Array.forEach() to determine which key-value pairs need to be deep cloned.

const deepClone = obj => {
if (Array.isArray(obj)){
	let arr = [];
	obj.forEach(
		(i,v) => (arr[i] = typeof v === 'object' ? deepClone(v) : v)
	)
	return arr;
}else {
	let clone = Object.assign({}, obj);
	Object.keys(clone).forEach(
	key => (clone[key] = typeof obj[key] === 'object' ? deepClone(obj[key]) : obj[key])
	);
	return clone;
}
};

const a = { foo: 'bar', obj: { a: 1, b: 2 } };
const b = deepClone(a); // a !== b, a.obj !== b.obj