Answer 1

sort(): [102, 15, 22, 29, 3, 8]
sort((a,b)=> a-b): [3, 8, 15, 22, 29, 102]

Answer 2

(一)var a = 1000100100 = 100 + 1001000 + 100100010000;
(二)var b = 1010010000 = 10000+100001000+100001000100;
a<b
但大头100001000100不变

Answer 3

感觉题目可以清晰一些，指定retry的入参是啥

 Promise.retry = function (fn, times) {
   return new Promise((rs, rj) => {
      return fn().then((res) => {
        rs(res)
      }).catch((err) => {
        if (--times >= 0) {
          return Promise.retry(fn, times)
        } else {
          rj(err)
        }
      })
   })
 }

我就想问这一句：return fn().then((res) => rs(res));
题目没说fn函数返回的一定是Promise吧？普通函数调用then不就报错了

Answer 4

function deepClone(obj, hash = new WeakMap()) {
    if (hash.has(obj)) return obj;
    var cobj;
    // null
    if (obj === null) { return obj }
    let t = typeof obj;

    // 基本类型
    switch (t) {
        case 'string':
        case 'number':
        case 'boolean':
        case 'undefined':
            return obj;
    }

    // 数组
    if (Array.isArray(obj)) {
        cobj = [];
        obj.forEach((c, i) => { cobj.push(deepClone(obj[i])) });
    } else {
        cobj = {};
        // object // symbol
        if (Object.prototype.toString.call(obj) === "[object Object]") {
            Object.getOwnPropertyNames(obj).concat(Object.getOwnPropertySymbols(obj)).forEach(c => {
                hash.set(obj, obj);
                cobj[c] = deepClone(obj[c], hash);
            });
        } else {
            //内置Object
            cobj = obj;
        }
    }
    return cobj;
}

var a=[];
a.push(a);
deepClone(a);