https://www.jianshu.com/p/d5f572dd3776
数组的扩展，两个数组的合并
const target = { a: 1 };
const source1 = { b: 2 };
const source2 = { c: 3 };
Object.assign(target, source1, source2);
target // {a:1, b:2, c:3}
原文：https://www.cnblogs.com/llllpzyy/p/11751177.html