XML? You're not alone.

XML It is not established, it is slowly developed. From the initial GML to SGML to the HTML, there was the 1998 Extensible Markup language developed over the years. XML , however, is not a technique for replacing HTML , and both are important.

XML is an extensible Markup language that is custom-designed to contain and transfer data. The recommended standard for the Internet's governing body.

XML The main applications:

1 , as a system configuration file

2 , AjAx transfer data in

3 , Web Server transfer data in

4 , heterogeneous platform data exchange and integration

XML is an Extensible Markup Language . To understand XMLWell, first look at how xml and HTML are related.

XML and the HTML The difference:

1. XML not to replace HTML of technology.

2. XML and the HTML designed for a variety of purposes

3. XML the core of the design is included in the transfer of data

4. HTML the core of the design is to display the data.

DTD : Document type definition

Its role is to define the legitimate building blocks of XML documents. It uses a series of legitimate elements to define the document structure.

DTD use:

1. Definition XML structure of the file

2, for XML file provides syntax and rules

3, the content can be defined in XML file, you can also define the XML outside the file

4. Use XML the industry or organization in which files are exchanged for data can define their own DTD

5. DTD for XML is an optional content

Why to use A DTD?

in order to exchange data correctly , the XML structure that needs to be determined .

Schema with the DTD Similarities and differences:

SCHEMASHIDTD successor; will be replaced in the future DTD

Schema Advantages :

Schema can be expanded for future needs; Schema more perfect, more powerful function; Schema based on XML preparation; Schema supports data types.

XML the syntax than HTML more stringent:

Note 1 : Match start and end tags

Note 2 : Nested tags cannot be nested

Note 3 : Case Sensitive

Note 4 : A XML there can only be one top-level element

CDATA :

when we want to output > , < , "" , "' , and so on, these symbols always go wrong and can't be lost . CADTA , s so that they can be output as is, complete the display.

< computer books >   <bookname<![ Cdata[oracle Applications <<<>>>> Large >>>>> "" "" "" "" "" "" ""]]></bookname >   <price>39.00</price></Computer Books >

Summary: XML can be widely used anywhere in the Web to meet the needs of network applications, making programming easier. And the code is clearer, easy to read and understand.

XML? You're not alone.