//数组去重

//利用splice

function unique1(list) {

    var i,j,len=list.length

    for(var i=0;i<len;i++){

        for(var j = i+1;j<len;j++){

            if(list[i] == list[j]){

                list.splice(j,1)

                len--;

                j--;

            }

        }

    }

    return list

}

console.log(unique1([1,2,2,2,2,4,3,3,4]))

//双循环去重法

function unique2(list) {

    var result = [];

    for(var i=0;i<list.length;i++){

        for(var j=i+1;j<list.length;j++){

             if(list[i]===list[j]){

                j= ++i

            }

        }

        result.push(list[i])

    }

    return result

}

console.log(unique2([1,2,2,2,2,4,3,3,4]))

// 利用对象键值对去重

function unique3(list) {

    var result = {};

    var r = []

    for(var i=0;i<list.length;i++){

        if(result.hasOwnProperty(list[i])){

        }else{

            result[list[i]] = [];

            r.push(list[i])

        }

    }

    return r

}

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

//sort思想

function unique4(list) {

    list.sort(function(a,b){

        return a-b

    })

    for(var i=0;i<list.length;i++){

        if(list[i]===list[i+1]){

            list.splice(i,1)

            i--

        }

    }

    return list

}

console.log(unique4([1,2,2,2,2,4,3,3,4]))

//利用indexOf以及forEach

function unique5(list) {

    var result = [];

    list.forEach(function(item,index){

        if(result.indexOf(item)<0){

            result.push(item)

        }

    })

    return result

}

console.log(unique5([1,2,2,2,2,4,3,3,4]))

// 利用Set数据结构

function unique6(list){

    return Array.from(new Set(list))

}

console.log(unique6([1,2,2,2,2,4,3,3,4]))