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What is
?
XML, Extensible Markup Language, extensible markup language. The suffix of the file is: .xml. Just like HTML is for displaying data, XML is for transmitting and storing data.
It is said that java is a professional language for operating XML.
What is it used for?
In order to facilitate data sharing and communication between different applications and different platforms.
The specific functions are:
(1) It can be used as a simple database to store and retrieve data;
( 2) Transmit files in the agreed format;
(3) Make software configuration files. [Configuration file: a file that saves software settings]
XML’s older brother——HTML
XML was born to improve the flaws and limitations of HTML.
The differences in usage are as follows:
XML’s best friend——JSON
JSON, Javascript Object Notation, js object notation. The function is also to store and exchange text information.
Comparison of the two: JSON is smaller, faster, easier to parse, so, and more popular than XML.
The scope of both: JSON is suitable for simple value transfer, and XML is suitable for a wider range.
XML data structure - tree structure
How it is implemented specifically, readers can refer to the code in the example below to understand at a glance.
It is worth noting that just like a book has only one root, XML can only have one root element.
Mind Map
##ExampleCode in the
.xml file:
<?xml version="1.0" encoding="UTF-8"?> <email xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="email.xsd"> <to>liuwei8809@163.com</to> <form>hellokitty@163.com</form> <title>about loving</title> <body>I love you forever!</body> <date>2008-11-12</date> </email>
Code in the .xsd file:
<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="email">
<xs:complexType>
<xs:sequence>
<xs:element name="to" type="xs:string"></xs:element>
<xs:element name="from" type="xs:string"></xs:element>
<xs:element name="title" type="xs:string"></xs:element>
<xs:element name="body" type="xs:string"></xs:element>
<xs:element name="date" type="xs:date"></xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</schema>Achieved effect:
For more related questions, please visit the PHP Chinese website: XML Video Tutorial
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