helloyoucan

``` const obj = {1:222, 2:123, 5:888} obj.length = 13 const array = Array.from(obj).map((item)=> item||null).slice(1,obj.length) console.log(array) ```

```javascript function reverse(nums){ const str = nums.toString() if(str.length===0){ return str } return str.slice(-1) + reverse(str.slice(0,-1)) } console.log(reverse(123456789)) ```

```javascript 'AbC'.split('').map((item)=>{ if(item.match(/[a-z]/)){ return item.toUpperCase() }else if(item.match(/[A-Z]/)){ return item.toLowerCase() } return item }).join('') ```

```javascript function change(str){ const arr = str.split(','); const result = []; let index = 0; for(let i = 0,l=arr.length;i1?`${prevArr[0]}~${prevArr[prevArr.length-1]}`:prevArr[0] } index++; } } const lastOne = result.pop(); result.push(lastOne.length>1?`${lastOne[0]}~${lastOne[lastOne.length-1]}`:lastOne[0]) return result.join(',')...

``` function random(){ return Array.from({length:10}).map(()=>parseInt(Math.random()*100)) } function insert(arr,value){ const _arr = [].concat([],arr); for(let i = 0, l = arr.length;ivalue){ _arr.splice(i,0,value); break; } } if(_arr.length===arr.length){ _arr.push(value) } return _arr } var...

```javascript // 0~99 function print(n){ setTimeout(() => { setTimeout(()=>{ console.log(n); },n*1000) }, Math.floor(Math.random() * 1000)); } for(var i = 0; i < 100; i++){ print(i); } ``` ```javascript // 99-0...

+1