简体中文(ZH-CN) English(EN) 繁体中文(ZH-TW) 日本語(JA) 한국어(KO) Melayu(MS) Français(FR) Deutsch(DE)
javascript - Why should this zero padding function be placed outside window.onload?
三叔
三叔 2017-07-05 10:45:30
0
3
802
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body style="background: black;color: #fff;font-size: 58px;">
    <img src="img/0.png" />
    <img src="img/0.png" />
    :
    <img src="img/0.png" />
    <img src="img/0.png" />
    :
    <img src="img/0.png" />
    <img src="img/0.png" />

    <script>
        function bul(n)
        {
            if(n<10)
            {
                return "0"+n;
            }
            else
            {
                return ""+n;
            }
        }

        window.onload=function()
        {
            var aImg = document.getElementsByTagName('img');
            var tell;
            tell=setInterval(function(){
                var myDate = new Date();
                var str = bul(myDate.getHours())+bul(myDate.getMinutes())+bul(myDate.getSeconds());
                for(var i=0;i<aImg.length;i++)
                {
                    aImg[i].src = "img/"+str[i]+".png";
                }    
            },500)
            
            tell();
        }

    </script>
</body>
</html>

Xiaobai doesn’t quite understand the reason, so I would like to ask seniors to explain it in detail. grateful.

三叔
三叔

reply all(3)
黄舟
黄舟2017-07-05 10:47:30 3 floor

Scope issue, put it outside, you can use it regardless of window.onload or window.onunload

The code placed in window.onload is just to ensure that the page is loaded, that the node actually exists, and that the node will not be unable to be selected

And your method of operating numbers, without node operations, can be placed inside or outside

Like +0
Add Reply
学霸
学霸2017-07-05 10:47:30 2 floor

window.onload event is executed when the page is completely loaded

$(function(){ }) is executed after the tags on the page are loaded

Like +0
Add Reply
淡淡烟草味
淡淡烟草味2017-07-05 10:47:30 1 floor

It can be used inside or outside. It can be shared when placed outside. It can only be used inside the onload event when placed inside.

Like +0
Add Reply
Popular Topics
More>
Popular Articles
Popular Tutorials
More>
Related Tutorials
Popular Recommendations
Latest courses
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn：Public welfare online PHP training，Help PHP learners grow quickly！