Question

//<![CDATA[
var displayCurrentTime = new function() {
  // Get values...
  var sysHour = getHours(); // Get Hours
  var curHour = 0; // Initialize current hour (12 hr format)
  var morningEvening = "AM"; // Initialize AM/PM notation

  if (sysHour < 13) { // If it's in the morning, set time as is.
    curHour = sysHour;
    morningEvening = "AM"
  } else {
    curHour = sysHour - 12; // If it's in the evening, subtract 12 from the value and use "PM"
    morningEvening = "PM"
  }
  var curMins: getMinutes; // Get current minutes...

  // Capture the ID of the notification bar div, and compose a string from the above values.
  var notificationBar = document.getElementById("notificationBar");
  var dateTimeString = curHour + ":" + curMins + " " + morningEvening;


  // All that code above files into this fun stuff.
  notificationBar.innerHTML = dateTimeString;
}

window.setInterval(function() {
  displayCurrentTime();
}, 1000);
//]]>

我一直在阅读一些信息，我想创建一个简单的脚本来获取小时和分钟，进行一些计算以确定它是AM还是PM，从这些结果中创建一个字符串变量，然后将其放入内部特定DIV元素的元素。它每秒执行一次。

根据我所阅读的内容，我编写的大多数代码似乎都有意义。在开始时，我尝试使用displayCurrentTime（）{}函数以及您在下面看到的内容（var displayCurrentTime = new function（）{}），但似乎都不起作用。我无法在页面上显示我的文字。注意：div的ID就是这里的NotificationBar，

此代码中是否有没有意义的东西，或者这实际上是否值得发布完整的HTML？

Answer 1

您不需要在新定义的函数前使用new，也无需实例化类。
您几乎没有语法错误，例如var curMins : ...而不是var curMins = ...。

此外，您不能在getHours()对象之外使用getMinutes()和Date方法：

var displayCurrentTime = function() {
                // Get values...
                var d = new Date();
                var sysHour = d.getHours();    // Get Hours
                var curHour = 0;             // Initialize current hour (12 hr format)
                var morningEvening = "AM";   // Initialize AM/PM notation
                    
                if (sysHour < 13) {          // If it's in the morning, set time as is.
                    curHour = sysHour;
                    morningEvening = "AM"
                } else {
                    curHour = sysHour - 12;  // If it's in the evening, subtract 12 from the value and use "PM"
                    morningEvening = "PM"
                }
                var curMins = d.getMinutes();     // Get current minutes...
                    
                var curSecs = d.getSeconds(); //optionally get seconds too 
                // Capture the ID of the notification bar div, and compose a string from the above values.
                var notificationBar = document.getElementById("notificationBar");
                var dateTimeString = curHour + ":" + curMins + ":" + curSecs + " " + morningEvening;
                    
                    
                // All that code above files into this fun stuff.
        notificationBar.innerHTML = dateTimeString;
            }
                
            window.setInterval(function(){ displayCurrentTime(); }, 1000);

<div id='notificationBar'>
Time Here 
</div>

请参见有关Date对象：

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

关于函数和匿名函数表达式：

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions#The_function_expression_(function_expression)

也：

https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Howto

Answer 2

您的函数中存在一些语法错误，我将一一介绍它们：

声明函数时，请勿使用new。只需将其放下=）var displayCurrentTime = function() {
您正在尝试使用:中的json语法var minutes: getMinutes将值分配给变量。您还忘记了执行该功能，因此请尝试var minutes = getMinutes();
在（2）中，我假设您已经声明了方法getHours和getMinutes，但是如果没有，则可以直接从新的Date对象调用它们：

var date = new Date();
var sysHours = date.getHours();
var minutes = date.getMinutes();
//...

应该这样做！

其他：您可以跳过将displayCurrentTime添加到setInterval函数内部的另一个函数中：window.setInterval(displayCurrentTime, 1000);

var displayCurrentTime = function() {
            var date = new Date();           // Get current date object
            var sysHour = date.getHours();   // Get Hours
            var curHour = 0;                 // Initialize current hour (12 hr format)
            var morningEvening;              // No need to initialize
            if (sysHour < 13) {              // If it's in the morning, set time as is.
                curHour = sysHour;
                morningEvening = "AM"
            } else {
                curHour = sysHour - 12;      // If it's in the evening, subtract 12 from the value and use "PM"
                morningEvening = "PM"
            }
            var curMins = date.getMinutes(); // Get Minutes
                
            // Capture the ID of the notification bar div, and compose a string from the above values.
            var notificationBar = document.getElementById("notificationBar");
            var dateTimeString = curHour + ":" + curMins + " " + morningEvening;

            // All that code above files into this fun stuff.
            notificationBar.innerHTML = dateTimeString;
        }
            
        window.setInterval(displayCurrentTime, 1000);

<div id='notificationBar'></div>

自定义代码以显示当前时间不起作用

2 个答案: