JavaScript dynamically changes HTML page elements such as adding or removing them

2020-03-30 03:41:23
OfStack

You can dynamically change elements in HTML through JavaScript

Add elements to HTML

You first need to create a tag, then add the appropriate content to the tag, and then add the created tag to the appropriate location.


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> 
<title> Test documentation </title> 
<script type="text/javascript"> 
function add(){ 
var element = document.createElement("p"); 
var node = document.createTextNode(" Add a new paragraph "); 
element.appendChild(node); 
x = document.getElementById("demo"); 
x.appendChild(element); 
} 
</script> 
</head> 
<body> 
<div id="demo"> 
<p> This is the first paragraph </p> 
</div> 
<input type="button" value=" button " onclick="add()" /> 
</body> 
</html>

Delete an element in HTML


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> 
<title> Test documentation </title> 
<script type="text/javascript"> 
function deleteE(){ 
var father = document.getElementById("demo"); 
var child = document.getElementById("p1"); 
father.removeChild(child); 
} 
</script> 
</head> 
<body> 
<div id="demo"> 
<p id="p1"> This is the first paragraph </p> 
<p id="p2"> This is the second paragraph </p> 
</div> 
<input type="button" value=" delete " onclick="deleteE()" /> 
</body> 
</html>