浅拷贝，深拷贝

const numbers = [3, 6, 9];
const numbersCopy = Array.from(numbers);
 
numbers === numbersCopy; // => false

只拷贝了一层，这是单层浅拷贝

 

下面是深拷贝（多层数组拷贝）

function recursiveClone(val) {
    return Array.isArray(val) ? Array.from(val, recursiveClone) : val;
}
 
const numbers = [[0, 1, 2], ['one', 'two', 'three']];
const numbersClone = recursiveClone(numbers);
 
numbersClone; // => [[0, 1, 2], ['one', 'two', 'three']]
numbers[0] === numbersClone[0] // => false

https://blog.csdn.net/JaxsonWang/article/details/101496076