千分位格式化 保留兩位小數

function toThousands(num) {
            var result = '';
            num = Number(num.toString() || 0).toFixed(2);
            var numAry = num.toString().split(".");
            var preNum = numAry[0];
            var lastNum = numAry[1];
            console.log(numAry);


            while (preNum.length > 3) {
                result = ',' + preNum.slice(-3) + result;
                preNum = preNum.slice(0, preNum.length - 3);
            }
            if (preNum) {
                result = preNum + result;
            }
            result=result+"."+lastNum;


            return result;
        }
        console.log(toThousands(1433298475.9483372));
        console.log(toThousands(0));