
What is XML Full Form? | XML VS HTML
- XML (Extensible Markup Language) is a widely used language for structuring and storing data in a human-readable and machine-readable format.
 - It is similar to HTML, but while HTML is used for presenting information on the web, XML is used to describe data.
 
What is XML used For?
- Self-Descriptive: XML documents are self-descriptive, meaning that they include information about the structure and content of the data they contain.
 - Hierarchical Structure: XML documents are organized hierarchically, with nested elements representing parent-child relationships.
 - Platform-Independent: XML is platform-independent, making it easy to share data between different systems.
 - Extensible: Users can define their tags and data structures, making XML highly extensible.
 - Text-Based: XML is human-readable and can be edited using a simple text editor.
 
XML Naming Rules
All XML elements and attributes must follow the naming rules:
- Names must start with a letter or underscore.
 - Names can only contain letters, numbers, hyphens, underscores, and periods.
 - Names are case-sensitive.
 
XML Document
An XML document consists of the following building blocks:
Elements
- XML elements are the fundamental components of an XML document. They are enclosed within angle brackets and can have attributes.
 - Elements can be nested inside other elements.
 
Example:
1<person>
2  <name>John Doe</name>
3  <age>30</age>
4</person>
5Attributes
- Attributes provide additional information about an element. They are name-value pairs and are defined within the start tag of an element.
 
Example:
1<person id="123" gender="male">
2  <name>John Doe</name>
3</person>
4Text Content
- Text content is the data enclosed within an element. It can be any text or numeric value.
 
Example:
1description>This is some text content.</description>XML VS HTML
HTML (Hypertext Markup Language) and XML serve different purposes:
- HTML is used for creating the structure and presentation of web pages. It is not as strict as XML and is designed for rendering in web browsers.
 - XML is used for structuring and storing data. It is more rigid and focused on describing the content and relationships within the data.
 
XML Parser
- XML parsers are software components that read and interpret XML documents. They help extract and manipulate data from XML.
 - Common XML parsers include DOM and SAX parsers in Java.
 
DTD (Document Type Definition)
- A DTD is used to define the structure and the legal elements and attributes of an XML document.
 - It acts as a schema for validating XML documents.
 
Example of a DTD declaration within an XML document:
1<!DOCTYPE library [
2  <!ELEMENT library (book+)>
3  <!ELEMENT book (title, author, year)>
4  <!ELEMENT title (#PCDATA)>
5  <!ELEMENT author (#PCDATA)>
6  <!ELEMENT year (#PCDATA)>
7]>
8<library>
9  <book>
10    <title>Sample Book</title>
11    <author>John Doe</author>
12    <year>2022</year>
13  </book>
14</library>
15XML with HTML
- XML can be embedded within HTML using the <xml> tag. This allows XML data to be displayed within an HTML page.
 
1<html>
2  <body>
3    <xml id="myData" src="data.xml"></xml>
4    <div>
5      <h3>XML Data</h3>
6      <div id="xmlContent"></div>
7    </div>
8  </body>
9</html>
10XML with CSS
- CSS can be used to style XML data when it is integrated with HTML. Selectors can target specific XML elements for styling.
 
1#xmlContent h4 {
2  font-weight: bold;
3  color: #333;
4}
5
6#xmlContent p {
7  color: #666;
8}
9XML with Javascript
1window.onload = function () {
2  var xmlData = document.getElementById("myData");
3  var xmlContent = document.getElementById("xmlContent");
4  var xmlDoc = xmlData.contentDocument;
5  
6  var name = xmlDoc.getElementsByTagName("name")[0].textContent;
7  var age = xmlDoc.getElementsByTagName("age")[0].textContent;
8  
9  xmlContent.innerHTML = "<h4>Name:</h4><p>" + name + "</p><h4>Age:</h4><p>" + age + "</p>";
10}
11Conclusion
XML is a way to store and structure data, like a digital filing system. It helps computers understand and share information easily.