04.展开运算符(ES6)

简版

• 针对可迭代对象展开
• 可以写在任意位置
• 针对普通对象展开

const nums = [1, 2, 3, 4, 5,63,21];
const nums_copy= nums.slice(0);
const nums_copy2= [1,1,1,1, ...nums,6,6,6];
const obj = {a: 1, b: 2, c: 3};
const obj_copy = {...obj, d: 4};
const objTonums = {...obj, ...nums};// 数组也是一个对象
console.log(Math.max.apply(null, nums)); // ES5
console.log(Math.max(...nums)); // ES6
console.log(nums_copy, nums_copy2); // [(7) [1, 2, 3, 4, 5, 63, 21] (7) [1, 1, 1, 1, 1, 2, 3, 4, 5, 63, 21, 6, 6, 6]]
console.log(obj_copy); // {a: 1, b: 2, c: 3, d: 4}
console.log(objTonums); // {a: 1, b: 2, c: 3, 0: 1, 1: 2, 2: 3, 3: 4, 4: 5, 5: 63, 6: 21}