Howie Zhou

> > ```js > > const findItem = (value, list, graph) => { > > return list.some(item => { > > if (item.id === value) { > > graph.push(item.id) >...

评论好多直接复制黏贴都是错的，发之前先测试一下啊，另外如果按照示例中省市区id的规则，可以找到目标 id 然后直接推倒出所有父 id 的吧.... ```javascript let res = [] let value = '112' for(let i = 0;i

```javascript var arr1 = ['A1', 'A2', 'B1', 'B2', 'C1', 'C2', 'D1', 'D2'] var arr2 = ['A', 'B', 'C', 'D'] const func = (arr1, arr2) => arr2.reduce((acc, cur) => [...acc, ...arr1.filter(item...

迭代的实现: ```javascript let arr = [1, 2, [3, 4, 5, [6, 7], 8], 9, 10, [11, [12, 13]]] const flatten = function (arr) { while (arr.some(item => Array.isArray(item))) { arr...

```javascript function convert(list) { let m = new Map() return list.reduce((pre,cur)=>{ m.set(cur.id,cur) let parent = m.get(cur.parentId) if( parent){ (parent.children || (parent.children = [])).push(cur) return pre } return [...pre,cur] },[]) }...

```javascript class LazyMan { constructor(name) { this.tasks = [] const task = () => { console.log(name) } this.tasks.push(task) setTimeout(() => { this.exec() }) } sleep(time) { const task = ()...

```javascript function func(str) { let arr = str.split(',') return arr.reduce((pre, cur) => { let lastItem = pre[pre.length - 1] let first = "" let last = lastItem if(!lastItem) return [...pre,cur]...

``` javascript function createArr(length,maxRange) { return Array.from(Array(length)).map(_ => Math.floor(Math.random() * maxRange)) } function transform(arr) { let res = []; [...new Set(arr)].forEach(item => (res[Math.floor(item / 10)] || (res[Math.floor(item / 10)] =...

**Object.fromEntries 是 ES10 语法，使用高版本的浏览器或者 NodeJs 版本运行** ```javascript function func(str) { let obj = str.split("").reduce((pre, cur) => { pre[cur] ? pre[cur]++ : pre[cur] = 1 return pre }, {}) let maxNum...

```javascript let x = [123, "meili", "123", "mogu", 123] let x1 = [123, [1, 2, 3], [1, "2", 3], [1, 2, 3], "meili"] let x2 = [123, {a: 1}, {a:...