越粑粑丶

```javascript var obj = {1:222, 2:123, 5:888} var arr = new Array(12).fill(null) for(key in obj){ arr[key-1] = obj[key] } arr // [222, 123, null, null, 888, null, null, null, null,...

```javascript const arr1 = ['A1', 'A2', 'B1', 'B2', 'C1', 'C2', 'D1', 'D2'] const arr2 = ['A', 'B', 'C', 'D'] const arr = new Array(arr2.length) const arrSum = [...arr1, ...arr2] for(let...

```javascript 一种方法：[...new Set(arr.toString().split(','))].sort((a, b)=>{return a-b}).map(Number) 还有：[...new Set(arr.flat(Infinity))].sort((a,b)=>{return a- b}) ```