數組去重的兩種方法（包括NaN去重）

（1）for循環

function delArr(arr) {
    var nan = [];

    for (var i = 0; i < arr.length; i++) {
        var temp = arr[i];
        if (typeof temp === 'number' && isNaN(temp)) {
            nan.push(temp);
            //删除多餘的NaN
            judge(i);
        } else {
            for (var j = i + 1; j < arr.length; j++) {
                if (arr[j] === temp) {
                    arr.splice(j, 1)
                }
            }
        }
    }
    function judge(index){
        if (nan.length > 1) {
            arr.splice(index, nan.length- 1)
        }
    }
    return arr;
}


console.log(delArr([false, true, undefined, null, NaN, 0, 1, {}, {}, 'a', 'a', NaN]))
           

（2）ES6 

function delArr1(arr){
    return Array.from(new Set(arr))
}

console.log(delArr([false, true, undefined, null, NaN, 0, 1, {}, {}, 'a', 'a', NaN]))