前端复习--Date小结

最近,总是遇到Date的应用,这里小结一下:

 Date 是 javascript中的对象

1 复制Date对象:

var birthday = new Date(1994, 12, 10);var copy = new Date();copy.setTime(birthday.getTime());

//这里需要复习的有,Date的初始化方法,

getTime, setTime 操作的都是毫秒数.

2 测量代码的执行时间

var end, start, i;start = new Date();for (i = 0; i < 1000; i++) {Math.sqrt(i);}end = new Date();console.log("Operation took " + (end.getTime() - start.getTime()) + " msec");

3 程序暂停特定时间

/* Wait for 5 seconds. */var start = (new Date()).getTime();while ((new Date()).getTime() - start < 5000);