XML — Syntax

XML Declaration

<?xml version="1.0" encoding="UTF-8"?>

Root Element

Every XML document must have exactly one root element:

<root>
    <child>Content</child>
</root>

Closing Tags

All tags must be closed:

<paragraph>Text</paragraph>
<empty/>

Case Sensitivity

Tags are case-sensitive:

<p>Lowercase</p>
<P>Uppercase</P>

Nesting

Elements must be properly nested:

<!-- Correct -->
<p><b>Bold text</b></p>

<!-- Incorrect -->
<p><b>Text</p></b>

Attributes

<book genre="fiction" pages="200">

Special Characters

Character	Entity
<	<
>	>
&	&
"	"
'	'

<note>Price: 5 &lt; 10 &amp; 10 &gt; 5</note>

Whitespace

XML preserves whitespace:

<name>
    John
    Doe
</name>

Rules Summary

1. Must have a root element
2. Tags must be closed
3. Tags are case-sensitive
4. Must be properly nested
5. Attribute values must be quoted
6. Special characters must be escaped

Mini Practice

1. Create a well-formed XML document
2. Use proper nesting
3. Escape special characters
4. Add attributes to elements

Up Next

Continue with Elements — creating XML elements.