XML Syntax

By: Prof. Fazal Rehman Shamil
Last modified on May 27th, 2019

Rule 1:

Root: 

Root Element is the parent of all other nodes.

Example:

<root>
  <First child>
    <First sub child>.</First sub child>
    <Second sub child>.</Second sub child> </First child>
</root>

Rule 2:

XML Pro log:

XML prolog is optional. If XML exists then  XML must come first in the document.

Example:

<?xml version=”1.0″ encoding=”UTF-8?>

Rule 3:

Case Sensitivity:

XML tags are case sensitive.

Example:

<author> sameed </author>

<AUTHOR> sameed <AUTHOR>

In this example both tags representing different tags.


Rule 4:

Attributes values must be qouted.

Example:

Wrong Practice Right Practice
<book date=12/11/2007>
  <title>Book On XML</title>
</book>
<book date=12/11/2007>
  <title>Book On XML</title>
</book>

Rule 5:

Comment:

Comment are used to give some opinion for better understanding.

Example:

< ! −− this is comment − − >

Rule 6:

Starting and closing of tags:

  • Every tag should have starting and ending.
  • For example <author> is the starting of author tag and </author> is the closing of the author tag.
  • Early starting tag should be late closed and late started tag should be early close. Example is shown in the diagram below.

tags in html