1.数组扁平化
上面的数据多层树状构造解决成只有一层children的构造
data = [ { name: "About", path: "/about", children: [ { name: "About US", path: "/about/us" }, { name: "About Comp", path: "/about/company", children: [ { name: "About Comp A", path: "/about/company/A", children: [ { name: "About Comp A 1", path: "/about/company/A/1" } ] } ] } ] }]// 解决后的构造[ { name: "About", path: "/about", children: [ { name: "About US", path: "/about/us" }, { name: "About Comp", path: "/about/company", }, { name: "About Comp A", path: "/about/company/A" }, { name: "About Comp A 1", path: "/about/company/A/1" } ] }]代码实现：
//递归遍历实现 var recursiveFunction3 = function(){ var aa=[] var cc=[] const getStr = function(data){ data.forEach(item => { aa.push({ name: item.name, path: item.path }) if(item.children?.length){ let children=getStr(item.children) } }) } getStr(data) cc.push({ name: aa[0].name, path: aa[0].path, children:aa.slice(1) }) // console.log(cc) } recursiveFunction3()代码基于上个根底优化：
var recursiveFunction4 = function(){ var aa=[] const getStr = function(data){ data.forEach(item => { aa.push({ name: item.name, path: item.path }) if(item.children?.length){ let children=getStr(item.children) } }) } getStr(data[0].children) //...开展运算符 因为前两项数据没变间接拿来用了拷贝 而后把最初一项children替换掉 aa= [{...data[0],children:aa}] console.log(aa) } recursiveFunction4()//基于recursiveFunction3()优化还有一种计划借鉴大佬的，代码如下:
//写了一个可自在定义扁平化层级的代码，level代码不扁平的层级function flatTree(data, level = 0, index = 0){ let result = [], obj; data.forEach(item => { result.push(obj = { name: item.name, path: item.path }) if(item.children?.length){ let children = flatTree(item.children, level, index + 1) if(level > index){ obj.children = children }else{ result = result.concat(children) } } }) return result}降维数组
//利用[].concat.apply实现降维 var arr=[[1,2],[3,4]]; function Jw(obj){ console.log(Array.prototype.concat.apply([],obj)) return Array.prototype.concat.apply([],obj); } Jw(arr);//如果concat办法的参数是一个元素，该元素会直接插入新数组中；如果参数是一个数组，该数组的各个元素将被插入到新数组中 function reduceDimension(arr){ let ret = []; for(let i=0;i<arr.length;i++){ ret=ret.concat(arr[i]) } console.log(ret) return ret; } reduceDimension(arr) //递归 function reduceDimension(arr){ let ret = []; let toArr = function(arr){ arr.forEach(function(item){ item instanceof Array ? toArr(item) : ret.push(item); }); } toArr(arr); console.log(ret) return ret; } reduceDimension([1, 2, [3, 4, [5, 6]]]) 排序
升序降序排序函数sortNumber
const arr1 = [6,1,2,3,4];function sortNumber(a,b){ return b-a;}arr1.sort(sortNumber);console.log(arr1)// [6, 4, 3, 2, 1]依照flag排序，为true的在后面显示
//其实这个和上边的原理是一样的等同，只是简写了const arr2 = [ { id: 10, flag: true }, { id: 5, flag: false }, { id: 6, flag: true }, { id: 9, flag: false }];const r = arr2.sort((a, b) => b.flag - a.flag);console.log(r);// [// { id: 10, flag: true },// { id: 6, flag: true },// { id: 5, flag: false },// { id: 9, flag: false }// ]