setTimeout、clearTimeout、setInterval,clearInterval ——小小计时器

先看下效果

话不多说上代码~

<!DOCTYPE HTML>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <title>计时器</title>
        <script type="text/javascript">
            var num=0;
            var i;
            function clockstart(){
                 document.getElementById('clock').value=num;
                 num++;
                 i=setTimeout("clockstart()",1000);
            }
            function clockstop(){
                clearTimeout(i);
            }
            function clockclear(){
                num=0;
                setTimeout("document.getElementById('clock').value=0",0);
                clearTimeout(i);
            }
        </script>
    </head>
    <body>
        <input type="text" id="clock" /><br/><br/>
        <input type="button" value="开始" onclick="clockstart()" />
        <input type="button" value="停止" onclick="clockstop()" />
        <input type="button" value="复位" onclick="clockclear()" />
    </body>
</html

代码

<!DOCTYPE HTML>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <title>秒表</title>
        <script type="text/javascript">
        function clock(){
            var time=new Date();
            var attime=time.getHours()+":"+time.getMinutes()+":"+time.getSeconds();
            document.getElementById('clock').value=attime;
        }
        setInterval("clock()",100);
        </script>
    </head>

    <body>
        <input type="text" id="clock" />
    </body>
</html>