Javascript若要添加小時數

Question

我有這個javascript代碼應該顯示時間。有用。我不能夠增加額外的時間。可以說我想加1小時。

 <script type="text/javascript"> 
     Date.prototype.addHours = function(h) {  
      this.setTime(this.getTime() + (h*60*60*1000)); 
      return this; 
     } 
     // This function gets the current time and injects it into the DOM 

     function updateClock() { 
      // Gets the current time 
      var now = new Date(); 

      // Get the hours, minutes and seconds from the current time 
      var hours = now.getHours(); 
      var minutes = now.getMinutes(); 
      var seconds = now.getSeconds(); 

      // Format hours, minutes and seconds 
      if (hours < 10) { 
       hours = "0" + hours; 
      } 
      if (minutes < 10) { 
       minutes = "0" + minutes; 
      } 
      if (seconds < 10) { 
       seconds = "0" + seconds; 
      } 

      // Gets the element we want to inject the clock into 
      var elem = document.getElementById('clock'); 

      // Sets the elements inner HTML value to our clock data 
      elem.innerHTML = hours + ':' + minutes + ':' + seconds; 
     } 
    function start(){ 
     setInterval('updateClock()', 200); 
    } 
    </script> 

第一個函數計算我想要添加的milisecons，第二個函數是「活動時鐘」。我如何在第二個函數中實現第一個函數，以便獲得工作結果？

Answer 1

添加小時，使用setHours：

// Gets the current time 
 
var now = new Date(); 
 

 
console.log("actual time:", now); 
 

 
now.setHours(now.getHours() + 1) 
 

 
console.log("actual time + 1 hour:", now);

爲引用：https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/setHours

Answer 2

看看這個fiddle。

這裏可以使用class Date的構造函數Date(milliseconds)。

以下是摘錄。

var now = new Date(); 
 
alert(now); 
 

 
var milliseconds = new Date().getTime() + (1 * 60 * 60 * 1000); 
 
var later = new Date(milliseconds); 
 
alert(later);

Answer 3

看看這個
fiddle here

的

var todayDate = new Date(); 
 
alert("After adding ONE hour : "+new Date(todayDate.setHours(todayDate.getHours()+1)));