js 去数组重复值

var arr = [1, 3, 2, 5, 2, 1, 4, 2, 1];
arr = arr.filter(function(item,index,array){
    return array.indexOf(item) === index;
  });
console.log(arr);

Array.prototype.unique3 = function(){
var res = [];
var json = {};
for(var i = 0; i < this.length; i++){
if(!json[this[i]]){
res.push(this[i]);
json[this[i]] = 1;
}
}
return res;
}
var arr = [112,112,34,'你好',112,112,34,'你好','str','str1'];
alert(arr.unique3());

function unite(arr1, arr2, arr3) {                        //数组拆嵌套再去重
    for(var i=1;i<arguments.length;i++)
    {
        arr1.push(arguments[i]);
    }
    const flatten = (arr) => {
        return arr.reduce(
            function(acc,val) {
            return acc.concat(Array.isArray(val) ? flatten(val) : val);
        },[]);
    };
    arr1 = flatten(arr1);
    // var obj = {};
    // var array = [];
    function unique(array1){
    return array1 = array1.filter(function(item,index,array){
    return array1.indexOf(item) === index;
  });
    }
    arr1 = unique(arr1);
    return arr1;
}
console.log(unite([1, 3, 2], [5, 2, 1, 4], [2, 1]));

标签：function,arr,return,arr1,重复,js,数组,112,var
来源： https://blog.csdn.net/YUlangML/article/details/121093185