巧用filter数组去重

 

1、set去重

var array= [1,2,2,3,4] 

var set = new Set(array) // {1,2,3,4}

var newArr = Array.from(set) // 再把set转变成array

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

2、filter去重

var array= [1,2,2,3,4] 

var newArr;

newArr = array.filter(function (element, index, self) {
    return self.indexOf(element) === index;
});

newArr = [1,2,3,4]

3、indexOf去重

var array = [1,2,2,3,4]

var newArr = []; 

for (var i = 0; i < array.length; i++) {

    if (newArr.indexOf(array[i]) == -1 ) {

        newArr.push(arr[i]); 

    } 
}