js实现数组去重的方法有哪些？js数组去重方法的简单介绍

function duplicates(arr) {
    var newArr=[]
    var newArr1=[]
    for(var i = 0;i<arr.length;i++){
       for(var j=0;j<arr.length;j++){
           if(i!=j){
               if(arr[i]==arr[j]){
                   newArr.push(arr[i])
               }
           }
       }
    }
        var json={}
        for(var i = 0; i < newArr.length; i++){
            if(!json[newArr[i]]){
                newArr1.push(newArr[i]);
                json[newArr[i]] = 1;
            }
        }
        return newArr1

}

function duplicates(arr) {
    var newArr=[]
    var newArr1=[]
    for(var i = 0;i<arr.length;i++){
       for(var j=0;j<arr.length;j++){
           if(i!=j){
               if(arr[i]==arr[j]){
                   newArr.push(arr[i])
               }
           }
       }
    }
       
    newArr1.push(newArr[0])
    for(var i=0;i<newArr.length;i++){
        var flag=0
        for(var j=0;j<newArr1.length;j++){
            if(newArr[i]==newArr1[j]) flag=1

        }
        if(flag==0) newArr1.push(newArr[i])
     }
        return newArr1

}

function duplicates(arr) {
   let newArr = arr;
   arr = [];
   let set = new Set();
   set(newArr);
   for (let i of set){
   arr.push(i);
  }
   return arr;
}