使用onload和setTimeout、setInterval来实现当前的时间

1.在body里面使用onload和在函数中使用setTimeout来实现当前的日期时间不断变化

2.在script中直接是用setInterval实现当前实现的日期时间不断变化

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title></title>
    </head>
    <body onload="fun()">
        <p id="demo"></p>
    <script>
        function fun()
        {var date=new Date();
        var year=date.getFullYear();
        var month=date.getMonth()+1;//这里用函数获取的日期是从0-11，所以要加1
        var datte=date.getDate();
        var hour=date.getHours();
        var minute=date.getMinutes();
        var second=date.getSeconds();
        if(minute<10)
        minute="0"+minute;
        if(second<10)
        second="0"+second;
        
        document.getElementById("demo").innerHTML=year+"年"+month+"月"+datte+"日"+hour+":"+minute+":"+second;
         setTimeout("fun()",1);
        
        }
    
        
    </script>
    </body>
</html>
<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title></title>
    </head>
    <body >
        <p id="demo"></p>
    <script>
        window.onload=fun();//单独这样写会更好
    function fun()
        {var date=new Date();
        var year=date.getFullYear();
        var month=date.getMonth()+1;
        var datte=date.getDate();
        var hour=date.getHours();
        var minute=date.getMinutes();
        var second=date.getSeconds();
        if(minute<10)
        minute="0"+minute;
        if(second<10)
        second="0"+second;
        
        document.getElementById("demo").innerHTML=year+"年"+month+"月"+datte+"日"+hour+":"+minute+":"+second;
         setTimeout("fun()",1);//使用clearTimeout来清除
        
        }
    
        
    </script>
    </body>
</html>
<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title></title>
    </head>
    <body >
        <p id="demo"></p>
    <script>
    function fun()
        {var date=new Date();
        var year=date.getFullYear();
        var month=date.getMonth()+1;
        var datte=date.getDate();
        var hour=date.getHours();
        var minute=date.getMinutes();
        var second=date.getSeconds();
        if(minute<10)
        minute="0"+minute;
        if(second<10)
        second="0"+second;
        
        document.getElementById("demo").innerHTML=year+"年"+month+"月"+datte+"日"+hour+":"+minute+":"+second;
        
        
        }
     setInterval("fun()",1);//自动循环，使用clearInterval来清除
        
    </script>
    </body>
</html>

 

时间会变化，秒钟更为明显

 

posted @ 2020-06-25 10:13  正好00  阅读(501)  评论(0)  编辑  收藏  举报