javascript实例——时间日期篇(包含5个实例)

本来想在网上找一些js实例来练练手，结果发现一本书《突破JavaScript编程实例五十讲》，看了下内容还不错，就下了下来；

后面又下了该书籍的源码，一看才发现这本书编的日期是2002年的，代码运行之后，有些代码可以运行，有些代码已经失效，原因是其所用的一些语言是已经淘汰的了。

其次就是由于是很早之前写的，那时候可能还没有css，js,html分离的想法，都是杂糅在一起的，看起来很不舒服。

还有就是，代码末尾都是不带分号的，还有各种不加关键字var的隐性全局变量等，都影响了程序的整洁性，简洁性。

于是就想，要不我把他的代码重新编写，来实现书中的要求。

在此，也对该书的作者马健兵等编著表示致敬，感谢他们的辛苦编著。

由于空间的限制，就不将js,css以单独文件存储了，全部都在html文件中，但已分离。

1、指定位置的时钟显示

时钟始终显示在网页的正中间，12小时制。

效果图：

源代码：

<!doctype html>

<html>

  <head>

  <meta charset="utf-8">

  <title>指定位置的时钟</title>

  <style>

    body{

      font-size: 30px;

      font-family: Arial;

      background: #fef4d9;

    }

    #Current-time{

      color:#66ff00;

      font-size: 30px;

    }

    #liveclock{

      position:absolute;

      top:50%;

      left: 50%;

      width: 250px;

      height: 100px;

      margin: -50px 0 0 -125px;

    }

    p{

      text-align: center;

      color:#ff00ff;

      margin: 0px;

    }

  </style>

  </head>

  <body>

    <div id="liveclock" >

      <div id="show"></div>

    </div>

    <script >

     function display()

     {

       var Digital=new Date();

       var hours=Digital.getHours();

       var minutes=Digital.getMinutes();

       var seconds=Digital.getSeconds();

       var dn="AM";

       if(hours>12)   //改成12小时制的

       {

         dn="PM";

         hours=hours-12;

       }

       if(hours==0)

         hours=12;

       if(minutes<=9)

         minutes="0"+minutes;  //改成两位数的显示

       if(seconds<=9)

         seconds="0"+seconds;

      var  myclock="<b><p id='Current-time'>Current time is:</p><p>"+hours+":"+minutes+":"+seconds+" "+dn+"</p></b>";

      var liveclock=document.getElementById("liveclock");

          liveclock.innerHTML=myclock;

      setTimeout("display()",1000);

     }

     display();

    </script>

  </body>

</html>

2、表针式时钟

由于书上的代码太老了，看不懂，自己重新写了一份。效果图如下：

源代码：

<!doctype html>

<html>

  <head>

    <meta charset="utf-8">

    <title>表针式时钟</title>

    <style>

    body{

      background: #fef4d9;

    }

    #time{

      position: absolute;

      width: 212px;

      height: 216px;

      top:50%;

      left: 50%;

      margin: -108px 0 0 -106px;

      border: 2px solid yellow;

    }

    .timeNum{

      position: absolute;

    }

    #pt0{

      position: absolute;

      top:20px;

      left: 105px;

      border: 4px solid red;

      height: 90px;

      z-index: 1px;

    }

    #pt1{

      position: absolute;

      top:35px;

      left: 105px;

      border: 4px solid blue;

      height: 75px;

      z-index: 100px;

    }

    #pt2{

      position: absolute;

      top:50px;

      left: 105px;

      border: 4px solid yellow;

      height: 60px;

      z-index: 110px;

    }

    </style>

  </head>

  <body>

    <div id="time">

      <div id="c0" class="timeNum" > </div>

      <div id="c1" class="timeNum"><b>1</b></div>

      <div id="c2" class="timeNum"><b>2</b></div>

      <div id="c3" class="timeNum"><b>3</b></div>

      <div id="c4" class="timeNum"><b>4</b></div>

      <div id="c5" class="timeNum"><b>5</b></div>

      <div id="c6" class="timeNum"><b>6</b></div>

      <div id="c7" class="timeNum"><b>7</b></div>

      <div id="c8" class="timeNum"><b>8</b></div>

      <div id="c9" class="timeNum"><b>9</b></div>

      <div id="c10" class="timeNum"><b>10</b></div>

      <div id="c11" class="timeNum"><b>11</b></div>

      <div id="c12" class="timeNum"><b>12</b></div>

      <div id="pt0" > </div>

      <div id="pt1" ></div>

      <div id="pt2" ></div>

    </div>

  </body>

  <script language=javascript>

    function getid(id){

      return document.getElementById(id);

    }

    //将数字以圆形的形式显示在屏幕上。根据三角函数的计算

    function clockNum(){

      for (var i=1; i<13;i++){

        var c1=getid("c"+i);

        angle=i*30/360*Math.PI*2;

        c1.style.top=0+(100-Math.cos(angle)*100)+"px";

        c1.style.left=100+Math.sin(angle)*100+"px";

      }

    }

    function clockRotate(){

      //获取当前的时间

      var start= new Date();

      var H=start.getHours();

      var M=start.getMinutes();

      var S=start.getSeconds();

      //设置其旋转的角度，分针每次6度，秒针每次6度，时针每次0.5度

      var mDu=M*6;

      var hDu=M*0.5+H*30;

      var sDu=S*6;

      var pt0=getid("pt0");

      var pt1=getid("pt1");

      var pt2=getid("pt2");

      //设置其绕末端旋转，宽度是在中间，高度是在整个高度的末尾，采用百分数的形式

      pt0.setAttribute('style',''+'transform:rotate('+ sDu +'deg); '+'transform-origin: center 93%;');

      pt1.setAttribute('style',''+'transform:rotate('+ mDu +'deg); '+'transform-origin: center 94%;');

      pt2.setAttribute('style',''+'transform:rotate('+ hDu +'deg); '+'transform-origin: center 95%;');

    }

    //每隔1毫秒检测一次

    setInterval(clockRotate,100);

    function init(){

      clockNum();

    }

     init();

    </script>

</html>

3、带按钮开关的form时钟

采用按钮的形式进行控制，按下开，显示时间和日期，按下关，则清空。效果图如下

源代码：

<!doctype html>

<html>

  <head>

    <meta charset="utf-8">

    <title>带按钮开关的Form时钟</title>

    <style>

      body{

        background: #aebcdf;

      }

      form{

        position:absolute;

        left:50;

        top:50;

        z-index:5;

      }

      input{

        color:red;

      }

      input[type="text"]{

        color: black;

      }

      .center{

        position: absolute;

        top:50%;

        left: 50%;

        transform: translate(-50%, -50%);

        border: 2px solid yellow;

        width: 220px;

        height: 42px;

        padding: 10px;

      }

    </style>

  </head>

  <body>

    <div class="center">

    <form name="clock" >

      <input type="text" name="disp" value="" size=30 onFocus="this.blur()" ><br>

      <input type="button" name="rad" value="off" id="offbtn" >关

      <input type="button" name="rad" value=" on" id="onbtn">开

    </form>

    <div>

  </body>

  <script>

      //公共事件

      var common={

        //获取id

        getid:function (id){

         return document.getElementById(id);

        },

        //绑定事件

        on:function (element,eventName,listener){

          if (element.addEventListener){

              element.addEventListener(eventName,listener,false);

          }

          else if (element.attachEvent){

              element.attachEvent('on'+eventName,listener);

          }

          else

              element['on'+eventName]=listener;

        },

      }

      //时间的方法与属性

      var time={

        //用来标记是开还是关，0表示关

        enabled:0,  

        //存储星期

        day:["星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"],

        //设定和显示时间

        //注意中间用了toLocaleString();

        Time_Set:function ()

        {

          var today = new Date();

          TM=window.setTimeout('time.Time_Set()', 1000);

          var timeStr=today.toLocaleString()+" "+time.day[today.getDay()];

          document.clock.disp.value = timeStr;

          console.log(today.toLocaleString());

        },

      }

      //全局定时函数名字

      var TM;

      //点击开事件

      var onbtn=common.getid("onbtn");

      common.on(onbtn,'click',function(){

        if(time.enabled == 0)

        {

          time.Time_Set();

          time.enabled = 1;

        }

      });

      //点击关事件

      var offbtn=common.getid("offbtn");

      common.on(offbtn,'click',function(){

        if( time.enabled==1 )

        {

          document.clock.disp.value='';

          clearTimeout( TM );

          time.enabled = 0;

        }

      });

    </script>

</html>

4、年龄提示器

网页打开时依次弹出3个输入对话框，分别需要你输入你的出生日期（年月日），然后显示内容，显示你的出生年月，距离下一次你的生日还有多少时间，以及你活了多少时间。效果图：

源代码：

<!doctype html>

<html>

  <head>

    <meta charset="utf-8">

    <title>年龄提示器</title>

    <style>

    div{

      position: absolute;

      top:50%;

      left: 50%;

      transform:translate(-50%,-50%);

      width: 375px;

      height: 200px;

      border: 2px solid red;

      padding: 20px;

    }

    p{

      margin: 0;

      margin-bottom: 10px;

    }

    input{

      margin-bottom: 10px;

    }

    </style>

  </head>

  <body bgcolor="f9fcb6" >

    <div>

      <form>

        <p id="birday"></p>

        <p id="age"></p>

        <input type="text" name="nextYear" size="47" value="">

        <p>I've been alive for...</p>

        <input type="text" name="liveYear" size="47" value="">

        <p>您已在本站停留了</p>

        <input type=text name="input1" size=10 value="">

        <br>

      </form>

    </div>

  </body>

  <script >

      function getid(id){

       return document.getElementById(id);

      }

      var timerID=window.setTimeout("showtime()",1);

      //弹出输入框，获取用户的出生日期,注意要把日期转化为数字

      var bMonth =parseInt(prompt('Which month were you born in?(月份)','1-12'));

      var bDate =parseInt(prompt('Which day were you born on?(天)','1-31'));

      var bYear =parseInt(prompt('Which year were you born in?(年份)','1900-'+new Date().getFullYear()));

      var tMonth = ['January','February','March','April','May','June','July','August','September','October','November','December'];

      var corrMonth = tMonth[bMonth-1];

      getid("birday").innerHTML=" I was born <b>"+corrMonth+", "+bDate+", "+bYear+"</b>. (<b>"+bMonth+"/"+bDate+"/"+bYear+"</b>)";

      //传入格式化后的时间，用来计算两个时间差，nextAgeDay > today

      function computeTime(nextAgeDay,today){

        var day={};

        var liveSec=nextAgeDay.getTime();

        var lTime = today.getTime();

        var daysec=24*60*60*1000;

        var hoursec=60*60*1000;

        var minsec=60*1000;

        var tt=(-lTime+liveSec);

        //计算时间差，天，小时，分，秒

        day._1day=Math.floor(tt/daysec);

        day._1hour=Math.floor((tt-day._1day*daysec)/hoursec);

        day._1min=Math.floor((tt-day._1day*daysec-day._1hour*hoursec)/minsec);

        day._1sec=Math.floor((tt-day._1day*daysec-day._1hour*hoursec-day._1min*minsec)/1000);        

        return day;

      }

      //计算距离下一岁还有多少天的时候，可以采用与现在的秒数相减getTime;

      function showtime()

      {

          //获取当前日期

        var today = new Date();

        var month = today.getMonth() + 1;

        var date = today.getDate();

        var year = today.getFullYear();

        //计算下一次生日是哪一年

        var nextAgeYear;

        var yourAge = year - bYear;

        if (bMonth < month || ((bMonth == month) && (date > bdate))) {

          yourAge--;

            nextAgeYear=year+1;

          }

        else {

            nextAgeYear=year;

          }

         //下一年几岁

        var nextAge = yourAge + 1;

        //将下一次生日时间格式化，默认时间在00:00;计算距离下一次生日还还有多长时间

        var nextAgeDay = new Date(""+nextAgeYear+","+bMonth+", "+bDate+" , 00:00");

        var day=computeTime(nextAgeDay,today);

        //将出生日期时间格式化，默认时间在00:00;计算已经活了多久了

        var bornAgeDay = new Date(""+bYear+","+bMonth+", "+bDate+" , 00:00");

        var lday=computeTime(today,bornAgeDay);

        //将结果输出

        document.forms[0].nextYear.value =""+day._1day+"days, "+day._1hour+"hours, "+day._1min+"minutes, "+day._1sec+"seconds";

        getid("age").innerHTML=" I am <b>"+yourAge+"</b> years old, and will turn <b>"+nextAge+"</b> in:";

        document.forms[0].liveYear.value =""+lday._1day+"days, "+lday._1hour+"hours, "+lday._1min+"minutes, "+lday._1sec+"seconds";

        timerID = window.setTimeout("showtime()",1000);

      }

     //第三个输入框,计算停留时间

      var sec=0;

      var min=0;

      var hou=0;

      var idt=window.setTimeout("update();",1);

      function update()

      {

        if(sec==60){sec=0;min+=1;}

        if(min==60){min=0;hou+=1;}

        document.forms[0].input1.value=hou+"时"+min+"分"+sec+"秒";

        idt=window.setTimeout("update();",1000);

        sec++;

      }

    </script>

</html>

5、得到文件的最后修改时间

本节主要讲获取HTML文件的最后修改时间。效果如下，其实跟前面的例子很像。

源代码：

<!doctype html>

<html>

  <head>

    <meta charset="utf-8">

    <title>获得文件的最后修改时间</title>

    <style>

    body{

      background: yellow;

    }

    .center{

     position: absolute;

      top:50%;

      left: 50%;

      transform:translate(-50%,-50%);

      width: 300px;

      height: 110px;

      border: 2px solid red;

      padding: 10px;

    }

    p{

      text-align: center;

      margin: 0px;

      padding: 10px;

    }

    </style>

</head>

<body>

  <script>

    //获得文件的格式化最后修改时间

    function DocDate()

    {

    var  StrofLastMod = document.lastModified;

    //获得文件的最后修改时间，它是一个string类型的变量。

    var months = ["January","February","March","April","May","June","July","August", "September","October","November","December"]; //月份名变量，供转换。

    var days = ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];//星期名变量，供转换

    var c = ":"; //用来分隔时，分，秒。

    var mdate =new Date(StrofLastMod);

    var month = months[mdate.getMonth()];

    var date = mdate.getDate();

    var year = mdate.getFullYear();

    var day = days[mdate.getDay()];

    var minutes=mdate.getMinutes();

    var hours= mdate.getHours();

    var seconds=mdate.getSeconds();

    var miliSec=mdate.getMilliseconds();

     var dateStr = year+" "+month+" "+date+" "+day+" "+hours+c+minutes+c+seconds+"."+miliSec; //获得格式化的文件最后修改时间。

    return dateStr;

  }

  var div=document.createElement("div");

  div.className="center";

  var divson=document.createElement("div");

  divson.innerHTML="<p>This File is last updated at:</p><p>"+DocDate()+"</p><p>"+document.lastModified+"</p>";

  div.appendChild(divson);

  document.body.appendChild(div);

  </script>

</body>

</html>