javascript倒计时功能实现代码_时间日期

 代码如下: 
/** 
* 倒计时 
* 
* @author WadeYu 
* @date 2012-04-20 17:40 
* @copyright boyaa.com 
*/ 
var TimeCountDown = function( initTime ){ 
var day = 0; 
var hour = 0; 
var minute = 0; 
var second = 0; 
var timerId = 0; 
var self = this; 
var fixInitTime = function(){ 
initTime = parseInt(initTime); 
if ( isNaN(initTime) || initTime < 0 ){ 
initTime = 0; 
} 
}; 
var fixZero = function(num){ 
return num < 10 ? ('0'+num) : num; 
}; 
var calc = function(){ 
showCallback.call(self, [fixZero(day), fixZero(hour), fixZero(minute), fixZero(second)]); 
if ( day === 0 && hour === 0 && minute === 0 && second === 0){ 
self.stop(); 
} else { 
if (hour === 0 && day > 0){ 
hour = 24; 
day--; 
} 
if (minute === 0 && hour > 0){ 
minute = 60; 
hour--; 
} 
if (second === 0 && minute > 0){ 
second = 59; 
minute--; 
} else { 
second--; 
} 
timerId = window.setTimeout(function(){ 
calc(); 
}, 1000); 
} 
}; 
var showCallback = function(){ 
alert('Please set show callback functions!'); 
}; 
var init = function(){ 
fixInitTime(); 
if ( initTime > 0 ){ 
day = Math.floor( (initTime / (24*60*60)) ); 
initTime -= day * 24*60*60; 
hour = Math.floor( initTime / (60*60) ); 
initTime -= hour * 60*60; 
minute = Math.floor( initTime / 60 ); 
second = initTime - minute * 60; 
} 
}; 
this.start = function(){ 
calc(); 
}; 
this.stop = function(){ 
timerId && window.clearTimeout(timerId); 
}; 
this.setShowCallback = function(fn){ 
typeof(fn) === 'function' ? (showCallback = fn) : ''; 
}; 
init(); 
}; 
 
示例如下: 
 代码如下: 
 
 
 
var timeCountDown = new TimeCountDown(3 * 24 * 60 * 60); 
timeCountDown.setShowCallback(function( obj ){ // [天, 小时, 分, 秒] 
document.getElementById('timeCon').innerHTML = obj[0] + ":" + obj[1] + ":" + obj[2] + ':' + obj[3]; 
}); 
timeCountDown.start();