javascript-为什么innerHTML替换无法运行？
[英]javascript - Why doesn't innerHTML replacing run?
问题描述
<!DOCTYPE HTML>
<html>
<head>
<script>
document.write("TEST1")
document.getElementById("demo").innerHTML="TEST2"
document.write("TEST3")
</script>
</head>
<body>
<p id="demo">TO_BE_REPLACED</p>
</body>
</html>
Here is the output: TEST1 
这是输出：TEST1
TO_BE_REPLACED
It seems the javascript executing stopped at document.getElementById("demo").innerHTML="TEST2" . 看来javascript执行已在document.getElementById("demo").innerHTML="TEST2"处停止。 Why doesn't it execute? 为什么不执行？
2 个解决方案
解决方案1
3 已采纳 2013-02-19 02:47:29
When the script is being run, <p id="demo"> does not exist yet . 运行脚本时， <p id="demo"> 尚不存在 。 Therefore, document.getElementById('demo') is returning null , which then triggers an error when you try to assign null.innerHTML = "TEST2" 因此， document.getElementById('demo')返回null ，然后在您尝试分配null时触发错误null.innerHTML = "TEST2"
This error stops all execution, so you never get to see the final TEST3 . 此错误将停止所有执行，因此您永远看不到最终的TEST3 。
解决方案2
1 2013-02-19 02:58:13
You need to enclose your script in a function that will be called when the window loads (using "window.onload" event). 您需要将脚本封装在加载窗口时将调用的函数中（使用“ window.onload”事件）。
<!DOCTYPE HTML>
<html>
<head>
<script>
function replaceDemoText()
{
document.getElementById("demo").innerHTML="TEST2";
}
window.onload = replaceDemoText;
</script>
</head>
<body>
<p id="demo">TO_BE_REPLACED</p>
</body>
</html>
声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.