js 數組去重的簡單方法

1. for + indexOf

var arr = [1, 1, true, true, 'false', 'false'];
var newArr = [];
for(var i = 0; i < arr.length; i++){
    if(newArr.indexOf(arr[i]) === -1){
        newArr.push(arr[i])
    }
}

2. filter + indexOf

var arr = [1, 1, true, true, 'false', 'false'];
var newArr = arr.filter(function(ele, ind, arr){
    return arr.indexOf(ele) === ind;
})
console.log(newArr); // [1, true, 'false']

3. set + from

var arr = [1, 1, true, true, 'false', 'false'];
var s = new Set(arr);
var newArr = Array.from(s);
// 或者 var newArr = [...s];
console.log(newArr); // [1, true, "false"]