对象操作

1.对象合并

var a = {name: 'Adele', age: 20}var b = {name: 'Chris', age: 20, address: 'beijing'}function update (...args) {return Object.assign(...args)}console.log(update(a, b))

2.阶乘

function factorial(n, acc = 1) {    if (n <= 1) return acc;    return factorial(n - 1, n * acc);}factorial(5)