JS浏览器对象-计时器

setInterval用法

 <!DOCTYPE html>
 <html>
 <head>
 <meta charset="UTF-8">
 <title>uvi</title>
      <link rel="stylesheet" href="style.css" type="text/css">
 </head>
 <body>
    <button id="btn" onclick="stopTime()">停止按钮</button>
    <p id="ptime"></p>
    <script>
       var mytime = setInterval(function(){
           getTime();
       }, );
       function getTime(){
           var d = new Date();
           var t = d.toLocaleTimeString();
           document.getElementById("ptime").innerHTML=t;
       }
       function stopTime(){
           clearInterval(mytime);
       }
    </script>

 </body>
 </html>

setTimeout用法

执行一次

 <!DOCTYPE html>
 <html>
 <head>
 <meta charset="UTF-8">
 <title>uvi</title>
      <link rel="stylesheet" href="style.css" type="text/css">
 </head>
 <body>
    <button id="btn" onclick="myWin()">执行按钮</button>
    <script>
      var win;
      function myWin(){//执行一次
          win = setTimeout(function(){
              alert("hello");
          }, );
      }
    </script>

 </body>
 </html>

循环执行

 <!DOCTYPE html>
 <html>
 <head>
 <meta charset="UTF-8">
 <title>uvi</title>
      <link rel="stylesheet" href="style.css" type="text/css">
 </head>
 <body>
    <button id="btn" onclick="myWin()">执行按钮</button>
    <script>
      var win;
      function myWin(){//执行一次
          alert("hello");
          win = setTimeout(function(){
              myWin();
          }, );
      }
    </script>

 </body>
 </html>

停止操作

clearTimeout(win);