【JS数组去重】JS几种数组去重方法

数组去重

var arr = [5,6,7,9,1,2,3,2,6,8,4,2,5,7,]

   
   
var obj = {};
var arr1 = [];
for(var i = 0 ; i < arr.length ; i++){  
    if(!obj[arr[i]]){  
        obj[arr[i]] = 1;  
        arr2.push(arr[i]);  
    }  
}  
console.log(arr1);

   
   
var arr1 = [];
for(var i=0;i < arr.length;){
    if(arr2.indexOf(arr[i]) < 0){
        arr2.push(arr[i]);
    }
}
console.log(arr2);

   
   
var arr3 = arr.filter((e,i,a)=>{
    return a.indexOf(e) === i ;
})
console.log(arr3)

   
   
arr4 = [...new Set(arr)]
console.log(arr4)