1. 單元素去重

//1. 雙重迴圈去重
var array = [1, 1, '1', '1',NaN,NaN];

function unique(array) {
    // res用來儲存結果
    var res = [];
    for (var i = 0, arrayLen = array.length; i < arrayLen; i++) {
        for (var j = 0, resLen = res.length; j < resLen; j++ ) {
            if (array[i] === res[j]) {
                break;
            }
        }
        // 如果array[i]是唯一的，那麼執行完迴圈，j等於resLen
        if (j === resLen) {
            res.push(array[i])
        }
    }
    return res;
}

console.log(unique(array)); // [1, "1"]

//利用indexof去重
function unique2(array){
    var res1=[];
    for(var i=0;i<array.length;i++){
        if(res1.indexOf(array[i])===-1){
            res1.push(array[i])
        }
    }
    return res1
}

console.log(unique2(array))

//利用indexof加filter
function unique3(array){

    var res=array.filter(function (item,index,array) {
        return array.indexOf(item)===index

    })
    return res
}

array=[2,3,4,[1,2],[1,2]]
console.log(unique3(array))

function unique4(array) {
    return Array.from(new Set(array));
}
array=[2,3,4,[1,2],[1,2],NaN,NaN]
console.log(unique4(array))
 

2. 物件去重

//去除陣列，物件
function uniqueObject(arr) {
    var hash = {};
    var result = arr.reduce(function(item, next) {
        hash[next.name] ? '' : hash[next.name] = true && item.push(next);
        return item
    }, [])
    return result
}


const arr = [1,1,NaN,NaN,'1',1,'1',
    {
        name:'tom',
        age:15
    },
    {
        name:'jack',
        age:18
    },
    {
        name:'tom',
        age:10
    }]

console.log(uniqueObject(arr))
 

3. 數組裡的基礎型別和物件去重

Array.prototype.quc=function(){
    var res=[];
    var jso={};
    for(var i=0;i<this.length;i++){
        if (!jso[JSON.stringify(this[i])]) {
            res.push(this[i]);
            jso[JSON.stringify(this[i])]=1;
        };  		}
        return res;
}


var s1=[{"a":10,b:20},{"a":10,b:20},{"a":60,c:30},{"f":60,d:30},1,1,1,'1','1',NaN,NaN];
console.log(s1.quc())