let arr = [12,1,12,3,1,88,66,9,66];
function unique(ary) {
        let s  = new Set(ary);
        // Array.from : 將set數(shù)據(jù)結(jié)構(gòu)轉(zhuǎn)成真正的數(shù)組；
        return  Array.from(s)
    }
    unique(arr);

let arr = [12,1,12,3,1,88,66,9,66];
function unique(ary) {
        let obj = {};
        for(let i=0;i<ary.length;i++){
            let cur = ary[i];
            if(obj[cur]){
                //ary.splice(i,1);// 導(dǎo)致數(shù)組塌陷
                ary[i]=ary[ary.length-1];
                ary.length--;// 刪除最后一項(xiàng)
                i--;
                continue;
            }
            obj[cur]=cur;// 給obj新增鍵值對；屬性名和屬性值是一樣的
        }
    }
    unique(arr);

let arr = [12,1,12,3,1,88,66,9,66];
 function unique(ary) {
        let newAry = [];
        for(let i=0;i<ary.length;i++){
            let  cur = ary[i];
            if(newAry.indexOf(cur)===-1){
                newAry.push(cur);
            }
        }
        return newAry;
    }
    unique(arr)

let arr = [12,1,12,3,1,88,66,9,66];
function unique(ary) {
       let a = ary.sort(function (a,b) {
           return a-b;
       });
       for(let i=0;i<a.length;i++){
           if(a[i]===a[i+1]){
               a.splice(i+1,1);
               i--;
           }
       }
       return a;
   }
   unique(arr)

let arr = [12,1,12,3,1,88,66,9,66];
function unique(ary) {
        let newAry = [];
        let len = ary.length;
        for(let i=0;i<len;i++){
            let cur = ary[i];
            if(!newAry.includes(cur)){
                newAry.push(cur);
            }
        }
        return newAry;
    }
    console.log(unique(arr));

let arr = [12,1,12,3,1,88,66,9,66];
function unique(ary) {
        let obj = {};
        return ary.filter(function (item,index,a) {
            // item : 數(shù)組每一個(gè)成員
            // index: 成員對應(yīng)的索引
            // a : 整個(gè)數(shù)組
            // hasOwnProperty來校驗(yàn)的該屬性是否出現(xiàn)過；
           return  obj.hasOwnProperty(typeof item+item)?false:obj[typeof item+item]=true;
           if(obj.hasOwnProperty(typeof item+item)){
               return false
           }else{
               obj[typeof item+item]=true;
               return true;
           }
        })
    }
    console.log(unique(arr))

let arr = [12,1,12,3,1,88,66,9,66];
    function unique(ary) {
        return ary.filter(function (item,index,a) {
            return ary.indexOf(item)===index;
        })
    }
    console.log(unique(arr));

let arr = [12,1,12,3,1,88,66,9,66];
 function unique(ary) {
        for(let i=0;i<ary.length;i++){
            for(j=i+1;j<ary.length;j++){
                if(ary[i]===ary[j]){
                    ary.splice(j,1);
                    j--;
                }
            }
        }
        return ary;
    }
    unique(arr);

let arr = [12,1,12,3,1,88,66,9,66];
function unique(ary) {
        let  len= ary.length;
        ary = ary.sort(function (a,b) {
            return a-b;
        });
        function loop(index) {
            if(index>=1){
                if(ary[index]===ary[index-1]){
                    ary.splice(index,1);
                }
                loop(index-1)
            }
        }
        loop(len-1);
        return ary;
    }
    console.log(unique(arr));

let arr = [12,1,12,3,1,88,66,9,66];
function unique(ary) {
        let newAry =[];
        let map = new Map();
        for(let i=0;i<ary.length;i++){
            if(!map.has(ary[i])){
                map.set(ary[i],true);
                newAry.push(ary[i]);
            }
        }
    }
    unique(arr);

let arr = [12,1,12,3,1,88,66,9,66];
function unique(ary) {
        // reduce : 第一個(gè)是函數(shù)，第二個(gè)參數(shù)會(huì)傳給第一次回調(diào)的prev;
        return ary.reduce((prev,next)=>{
            // 該函數(shù)返回值是下一次執(zhí)行的prev;
            return prev.includes(next)?prev:[...prev,next];
        },[])
    }
    console.log(unique(arr));

let  arr = [12,1,12,3,1,88,66,9,66];
    let a = [...new Set(arr)];
    console.log(a);