js中 Date对象
这个对象主要是用于操作日期和时间的
例子：用Date()得到当前的日期
<html>
<body>
<script type="text/javascript">
document.write(Date())
</script>
</body>
</html>
下面一个getTime()
用他来计算从１９７0年一共过了多少年
<html> <body> <script type="text/javascript"> var minutes = 1000*60 var hours = minutes*60 var days = hours*24 var years = days*365 var d = new Date() var t = d.getTime() var y = t/years document.write("It's been: " + y + " years since 1970/01/01!") </script> </body> </html>
下面一个是setFullYear()，用他来设置一个特殊的日期
<html> <body> <script type="text/javascript"> var d = new Date() d.setFullYear(1992,10,3) document.write(d) </script> </body> </html>
下面是一个toUTCString()，他用于把日期转换成ＵＴＣ格式
<html> <body> <script type="text/javascript"> var d = new Date() document.write (d.toUTCString()) </script> </body> </html>
下面是一个getDay()用这个和一个数组来返回一个星期，不仅仅是一个数字哦，
<html> <body> <script type="text/javascript"> var d=new Date() var weekday=new Array(7) weekday[0]="Sunday" weekday[1]="Monday" weekday[2]="Tuesday" weekday[3]="Wednesday" weekday[4]="Thursday" weekday[5]="Friday" weekday[6]="Saturday" document.write("Today it is " + weekday[d.getDay()]) </script> </body> </html>
怎么在一个页面上展现一个时钟呢，下面的代码可以帮助我们
<html> <head> <script type="text/javascript"> function startTime() { var today=new Date() var h=today.getHours() var m=today.getMinutes() var s=today.getSeconds() // add a zero in front of numbers<10 m=checkTime(m) s=checkTime(s) document.getElementById('txt').innerHTML=h+":"+m+":"+s t=setTimeout('startTime()',500) } function checkTime(i) { if (i<10) {i="0" + i} return i } </script> </head>
Date Object Methods
FF: Firefox, N: Netscape, IE: Internet Explorer
| Method | Description | FF | N | IE |
|---|---|---|---|---|
| Date() | Returns today's date and time | 1 | 2 | 3 |
| getDate() | Returns the day of the month from a Date object (from 1-31) | 1 | 2 | 3 |
| getDay() | Returns the day of the week from a Date object (from 0-6) | 1 | 2 | 3 |
| getMonth() | Returns the month from a Date object (from 0-11) | 1 | 2 | 3 |
| getFullYear() | Returns the year, as a four-digit number, from a Date object | 1 | 4 | 4 |
| getYear() | Returns the year, as a two-digit or a four-digit number, from a Date object. Use getFullYear() instead !! | 1 | 2 | 3 |
| getHours() | Returns the hour of a Date object (from 0-23) | 1 | 2 | 3 |
| getMinutes() | Returns the minutes of a Date object (from 0-59) | 1 | 2 | 3 |
| getSeconds() | Returns the seconds of a Date object (from 0-59) | 1 | 2 | 3 |
| getMilliseconds() | Returns the milliseconds of a Date object (from 0-999) | 1 | 4 | 4 |
| getTime() | Returns the number of milliseconds since midnight Jan 1, 1970 | 1 | 2 | 3 |
| getTimezoneOffset() | Returns the difference in minutes between local time and Greenwich Mean Time (GMT) | 1 | 2 | 3 |
| getUTCDate() | Returns the day of the month from a Date object according to universal time (from 1-31) | 1 | 4 | 4 |
| getUTCDay() | Returns the day of the week from a Date object according to universal time (from 0-6) | 1 | 4 | 4 |
| getUTCMonth() | Returns the month from a Date object according to universal time (from 0-11) | 1 | 4 | 4 |
| getUTCFullYear() | Returns the four-digit year from a Date object according to universal time | 1 | 4 | 4 |
| getUTCHours() | Returns the hour of a Date object according to universal time (from 0-23) | 1 | 4 | 4 |
| getUTCMinutes() | Returns the minutes of a Date object according to universal time (from 0-59) | 1 | 4 | 4 |
| getUTCSeconds() | Returns the seconds of a Date object according to universal time (from 0-59) | 1 | 4 | 4 |
| getUTCMilliseconds() | Returns the milliseconds of a Date object according to universal time (from 0-999) | 1 | 4 | 4 |
| parse() | Takes a date string and returns the number of milliseconds since midnight of January 1, 1970 | 1 | 2 | 3 |
| setDate() | Sets the day of the month in a Date object (from 1-31) | 1 | 2 | 3 |
| setMonth() | Sets the month in a Date object (from 0-11) | 1 | 2 | 3 |
| setFullYear() | Sets the year in a Date object (four digits) | 1 | 4 | 4 |
| setYear() | Sets the year in the Date object (two or four digits). Use setFullYear() instead !! | 1 | 2 | 3 |
| setHours() | Sets the hour in a Date object (from 0-23) | 1 | 2 | 3 |
| setMinutes() | Set the minutes in a Date object (from 0-59) | 1 | 2 | 3 |
| setSeconds() | Sets the seconds in a Date object (from 0-59) | 1 | 2 | 3 |
| setMilliseconds() | Sets the milliseconds in a Date object (from 0-999) | 1 | 4 | 4 |
| setTime() | Calculates a date and time by adding or subtracting a specified number of milliseconds to/from midnight January 1, 1970 | 1 | 2 | 3 |
| setUTCDate() | Sets the day of the month in a Date object according to universal time (from 1-31) | 1 | 4 | 4 |
| setUTCMonth() | Sets the month in a Date object according to universal time (from 0-11) | 1 | 4 | 4 |
| setUTCFullYear() | Sets the year in a Date object according to universal time (four digits) | 1 | 4 | 4 |
| setUTCHours() | Sets the hour in a Date object according to universal time (from 0-23) | 1 | 4 | 4 |
| setUTCMinutes() | Set the minutes in a Date object according to universal time (from 0-59) | 1 | 4 | 4 |
| setUTCSeconds() | Set the seconds in a Date object according to universal time (from 0-59) | 1 | 4 | 4 |
| setUTCMilliseconds() | Sets the milliseconds in a Date object according to universal time (from 0-999) | 1 | 4 | 4 |
| toSource() | Represents the source code of an object | 1 | 4 | - |
| toString() | Converts a Date object to a string | 1 | 2 | 4 |
| toGMTString() | Converts a Date object, according to Greenwich time, to a string. Use toUTCString() instead !! | 1 | 2 | 3 |
| toUTCString() | Converts a Date object, according to universal time, to a string | 1 | 4 | 4 |
| toLocaleString() | Converts a Date object, according to local time, to a string | 1 | 2 | 3 |
| UTC() | Takes a date and returns the number of milliseconds since midnight of January 1, 1970 according to universal time | 1 | 2 | 3 |
| valueOf() | Returns the primitive value of a Date object | 1 | 2 | 4 |
Date Object Properties
| Property | Description | FF | N | IE |
|---|---|---|---|---|
| constructor | A reference to the function that created the object | 1 | 4 | 4 |
| prototype | Allows you to add properties and methods to the object | 1 | 3 | 4 |
