whirring

``` const arr = []; let idx = 0; function filter() { const num = Math.floor(Math.random() * 31 + 2); while (idx < 5) { if (!arr.includes(num)) { arr.push(num); idx++;...

``` js function trans() { const arr = []; for (let i = 1; i < 12; i++) { arr.push(obj[i] || null); } return arr; } ```

``` js str .split('') .reverse() .reduce( (str, v) => (str += v === v.toLocaleLowerCase() ? v.toLocaleUpperCase() : v.toLocaleLowerCase()), '' ); ```

好像写了好多.... ``` js function convert() { let res = ''; for (let i = 0; i < arr.length; i++) { const cur = arr[i]; res += cur + (cur +...

``` js function trans(arr) { let res = []; const newArr = [...new Set(arr.sort((a, b) => a - b))]; // 数组排序 for (let i = 0; i < newArr.length; )...

``` js function maxStr(str) { const arr = str.split(''); let obj = {}; let max = 1; let maxValue = arr[0]; for (let i = 0; i < arr.length; i++)...

> #### 一次遍历 > ```js > function findLongest(str) { > if (!str) return {} > let count = 0 > let maxCount = 0 > let cur = str[0] >...

``` function del(str, n) { str = [...str] const idx = str.lastIndexOf(n); return str.splice(idx, 1).join(''); } ```

``` function count(str, param) { const reg = new RegExp(param, 'g'); return str.match(reg).length; } ```

1. 创建一个空对象，作为要返回的对象实例 2. 将这个对象的原型，指向构造函数的prototype属性 3. 将这个空对象赋值给函数内部的this关键字 4. 开始执行构造函数内部的代码 ``` function newF(obj) { const o = {}, args = [].slice.call(arguments); o.__ptoto__ = obj.prototype; const res = obj.apply(o, args.slice(1)); return typeof res...