JS 生成唯一数字

 1 function uniqueNumber() { 2 ????var date = Date.now(); 3 ?????4 ????if (date <= uniqueNumber.previous) { 5 ????????date = ++uniqueNumber.previous; 6 ????} else { 7 ????????uniqueNumber.previous = date; 8 ????} 9 10 ????return date;11 }12 13 uniqueNumber.previous = 0;14 15 function ID(){16 ??return uniqueNumber();17 };