Question

我正在尝试从JS初学者那里制作一个日期和时间脚本，我相信你们之前有人已经看过这个。

我不确定我哪里出错了，并且我正在努力解决问题，因为日志只是吐出'错误'。

任何人都可以为我清楚，坚持我编写脚本的一般方式。解释会很棒！

var date = new Date();

var day = date.getDay();
var hour = date.getHours();
var min = date.getMinutes();
var sec = date.getSeconds();

var weekdays = [Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday];
var today = weekdays[day];

var amPm = amPmFunc;
function amPmFunc() {
    if(hour < 12) {
        amPm = AM;
    } else { 
        amPm = PM;
    }
}

console.log("Today is: " + today);
console.log("Current time is: " + hour + amPM + ":" + min + ":" + "sec");

Answer 1

首先，您忘记用''括起一些字符串。即Sunday应为'Sunday'。

另外 - 请记住 - Javascript 具有案例性。因此，名为amPm的变量将不会被识别为amPM。

此外，您的函数amPmFunc应返回一个值，而不是设置全局变量的值。它只是这样整洁。当你打电话给它时，用括号称呼它：var amPm = amPmFunc();。

但除此之外 - 干得好！ ☻

见这个固定的例子：

＆＃13;

var date = new Date();

var day = date.getDay();
var hour = date.getHours();
var min = date.getMinutes();
var sec = date.getSeconds();

var weekdays = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
var today = weekdays[day];

var amPm = amPmFunc();

function amPmFunc() {
    if(hour < 12) 
        return 'AM';
    else 
        return 'PM';
}

console.log("Today is: " + today);
console.log("Current time is: " + hour + amPm + ":" + min + ":" + "sec");

＆＃13;

Answer 2

为什么？

Array declaration 错误。请注意格式化数组中字符串的引号
Javascript是case sensitive one。所以不要忘记信的情况
对于函数声明，您可以使用()之类的var amPm = amPmFunc()。并在ampm函数上添加return statement，否则返回undefined。

我的建议：为了更好地学习如何申报variable，功能和 js中的字符串

var date = new Date();

var day = date.getDay();
var hour = date.getHours();
var min = date.getMinutes();
var sec = date.getSeconds();

var weekdays = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
var today = weekdays[day];

var amPm = amPmFunc()

function amPmFunc() {
  if (hour < 12) {
     amPm = 'AM';
  } else {
    amPm = 'PM';
  }
  return amPm
}

console.log("Today is: " + today);
console.log("Current time is: " + hour + amPm + ":" + min + ":" + "sec");

Answer 3

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      <div class="container-fluid-nav text-center">
            <ul class="nav navbar-nav">
               <li><a href="#">CSGO</a>
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               <li><a href="#">PUBG</a>
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               <li><a href="#">External Links</a>
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            </ul>
      </div>
      </nav>
      <div class="footer navbar-fixed-bottom">
         <p class="footer-text">Copyright 2017 ©</p>
      </div>
      <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
      <script src="script.js"></script>
      <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
      <script src="js/bootstrap.min.js"></script>
   </body>

他们应该是字符串。

var weekdays = [Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday];

Answer 4

所有字符串必须位于＆＃34;
name_of_function（）;而是name_of_function
函数必须返回某些东西，你的amPmFunc（）没有返回amPm

    var date = new Date();

var day = date.getDay();
var hour = date.getHours();
var min = date.getMinutes();
var sec = date.getSeconds();

var weekdays = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
var today = weekdays[day];


function amPmFunc() {
    if(hour < 12) {
        amPm = "AM";
    } else { 
        amPm = "PM";
    }

    return amPm;
}
var amPM = amPmFunc();
console.log("Today is: " + today);
console.log("Current time is: " + hour + amPM + ":" + min + ":" + "sec");

Answer 5

试试这个

var date = new Date();
var day = date.getDay();
var hour = date.getHours();
var min = date.getMinutes();
var sec = date.getSeconds();

var weekdays = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
var today = weekdays[day];

var amPm = '';
    if(hour < 12) {
        amPm = 'AM';
    } else if (hour > 12){ 
        hour = hour - 12;
        amPm = 'PM';
    } else {
        amPm = 'PM'
    }
console.log("Today is: " + today);
console.log("Current time is: " + hour + amPm + ":" + min + ":" + sec);

日期和时间脚本

5 个答案: