// 最簡(jiǎn)單數(shù)組去重法
/*
* 新建一新數(shù)組，遍歷傳入數(shù)組，值不在新數(shù)組就push進(jìn)該新數(shù)組中
* IE8以下不支持?jǐn)?shù)組的indexOf方法
*/
function uniq(array){
  var temp = []; //一個(gè)新的臨時(shí)數(shù)組
  for(var i = 0; i < array.length; i++){
    if(temp.indexOf(array[i]) == -1){
      temp.push(array[i]);
    }
  }
  return temp;
}
var newArray = [1,2,2,4,9,6,7,5,2,3,5,6,5];
console.log(uniq(newArray));// [1, 2, 4, 9, 6, 7, 5, 3]
/*
var newArray = ['mu','zi','dig','big','z','mu','zi','muzidigbig']
console.log(uniq(newArray));//["mu", "zi", "dig", "big", "z", "muzidigbig"]
*/

/*
* 還是得調(diào)用“indexOf”性能跟方法1差不多，
* 實(shí)現(xiàn)思路：如果當(dāng)前數(shù)組的第i項(xiàng)在當(dāng)前數(shù)組中第一次出現(xiàn)的位置不是i，
* 那么表示第i項(xiàng)是重復(fù)的，忽略掉。否則存入結(jié)果數(shù)組。
*/
function uniq(array){
  var temp = [];
  for(var i = 0; i < array.length; i++) {
    //如果當(dāng)前數(shù)組的第i項(xiàng)在當(dāng)前數(shù)組中第一次出現(xiàn)的位置是i，才存入數(shù)組；否則代表是重復(fù)的
    if(array.indexOf(array[i]) == i){
      temp.push(array[i])
    }
  }
  return temp;
}
var aa = [1,2,"2",4,9,"a","a",2,3,5,6,5];
console.log(uniq(aa));//[1, 2, "2", 4, 9, "a", 3, 5, 6]

/*
* 給傳入數(shù)組排序，排序后相同值相鄰，
* 然后遍歷時(shí),新數(shù)組只加入不與前一值重復(fù)的值。
* 會(huì)打亂原來數(shù)組的順序
*/
function uniq(array){
  array.sort();
  console.log(array.sort());
  var temp=[array[0]];
  for(var i = 1; i < array.length; i++){
    if( array[i] !== temp[temp.length-1]){
      temp.push(array[i]);
    }
  }
  return temp;
}
var aa = [1,2,"2",4,9,"a","a",2,3,5,6,5];
console.log(uniq(aa));//[1, "2", 2, 3, 4, 5, 6, 9, "a"]

// 思路：獲取沒重復(fù)的最右一值放入新數(shù)組
/*
* 推薦的方法
* 方法的實(shí)現(xiàn)代碼相當(dāng)酷炫，
* 實(shí)現(xiàn)思路：獲取沒重復(fù)的最右一值放入新數(shù)組。
* （檢測(cè)到有重復(fù)值時(shí)終止當(dāng)前循環(huán)同時(shí)進(jìn)入頂層循環(huán)的下一輪判斷）
*/
function uniq(array){
  var temp = [];
  var index = [];
  var l = array.length;
  for(var i = 0; i < l; i++) {
    for(var j = i + 1; j < l; j++){
      if (array[i] === array[j]){
        i++;
        j = i;
      }
    }
    temp.push(array[i]);
    index.push(i);
  }
  console.log(index);//[0, 2, 5, 6, 7, 8, 9]
  return temp;
}
var aa = [1,2,2,3,5,3,6,5,'3','muzi'];
console.log(uniq(aa));// [1, 2, 3, 6, 5, "3", "muzi"]

//利用數(shù)組原型對(duì)象上的includes方法
function unique(arr){
 var bArr= [];
 for(var i=0; i<arr.length; i++){
  if( !bArr.includes(arr[i]) ){ // 如果bArr新數(shù)組包含當(dāng)前循環(huán)item
   bArr.push(arr[i]);
  }
 }
 return bArr;
}
var aa = [1,2,2,3,5,3,6,5,'3','muzi'];
console.log(unique(aa))//[1, 2, 3, 5, 6, "3", "muzi"]

//利用數(shù)組原型對(duì)象上的filter和includes方法
function unique6(arr){
 var bArr= [];
 bArr= arr.filter(function(item){
 return bArr.includes(item) ? null : bArr.push(item);
 });
 return bArr;
}
var aa = [1,2,2,3,5,3,6,5,'3','muzi'];
console.log(unique6(aa))//[1, 2, 3, 5, 6, "3", "muzi"]

//利用數(shù)組原型對(duì)象上的forEach和includes方法
function unique7(arr){
 var bArr= [];
 arr.forEach(function(item){
  bArr.includes(item) ? null : bArr.push(item);
 }); 
 return bArr;
}
var aa = [1,2,2,3,5,3,6,5,'3','muzi'];
console.log(unique7(aa))//[1, 2, 3, 5, 6, "3", "muzi"]

  Array.prototype.method1 = function(){
    var arr=[];  //定義一個(gè)臨時(shí)數(shù)組
    for(var i = 0; i < this.length; i++){  //循環(huán)遍歷當(dāng)前數(shù)組
      //判斷當(dāng)前數(shù)組下標(biāo)為i的元素是否已經(jīng)保存到臨時(shí)數(shù)組
      //如果已保存，則跳過，否則將此元素保存到臨時(shí)數(shù)組中
      if(arr.indexOf(this[i]) == -1){
        arr.push(this[i]);
      }
    }
    return arr;
  };
  var arrNum1 = [1,4,1,1,3,3,4,6,7,8,3,7,0,2,11,2,'muzi','digbig','muzi'];
  console.log(arrNum1.method1());//[1, 4, 3, 6, 7, 8, 0, 2, 11, "muzi", "digbig"]

  let arr = [1,2,2,3,4,4,4];
  let s = new Set(arr);
  //結(jié)果：Set {1,2,3,4}
  let newArr = Array.from(s);
  //結(jié)果：[1,2,3,4],完成去重