携程2018秋招笔试题解（前端）

let str="携程C2t0r1i8p2020校招";
let nums=str.match(/\d/g);
let chars=str.match(/[A-Za-z]/g);
nums=[...new Set(nums)];
let s="";
nums.forEach(e=>s+=e);
chars.forEach(e=>s+=e);
console.log(s);

let str=[null, 2, "test", undefined, {
    "type": "product",
    "content": "product1"
},  {
    "type": "product",
    "content": "product2"
},  {
    "type": "tag",
    "content": "tag1"
}, {
    "type": "product",
    "content": "product3"
}, {
    "type": "tag",
    "content": "tag2"
}];
function groupList(list) {
    if (Object.prototype.toString.call(list) !== '[object Array]') 
        return [];     
    for(let i=list.length-1;i>=0;i--){
        if(list[i]==null||typeof list[i]!="object"){
            list.splice(i,1);
        }
    }
    let types=[];
    for(let i=list.length-1;i>=0;i--){
        types.push(list[i].type);
    }
    types=[...new Set(types)]
    let product=[],tag=[],res=[];
    for(let j=0;j<types.length;j++){
        let newType=[];
        for(let i=list.length-1;i>=0;i--){
            if(list[i].type==types[j]){
                newType.unshift(list[i].content);
            }
        }
        res.push(newType);
    }
    let res2=[];
    for(let j=types.length-1;j>=0;j--){
        let tmp={type:types[j],content:res[j]}
        res2.push(tmp);
    }
    return res2;
}
var data =str;
var result = groupList(data);
console.log(JSON.stringify(result));

function map(data, fn) {
    let res;
    if (Object.prototype.toString.call(data) === '[object Array]') {
        res = []
        data.forEach(function (v, i, arr) {
            res.push(fn(v, i, arr));
        })
        return res;
    } else if (Object.prototype.toString.call(data) === '[object Object]') {
        res = {};
        for (let key in data) {
            res[key] = fn(data[key], key, data);
        }
        return res;
    }
    return null;
}