XML❤You are not alone, XML? Lonely

XML: you are not alone. XML? Lonely

XML is not an existing one. It is developed slowly. From the initial development of GML to SGML and then to HTML, it was finally a scalable markup language developed in 1998. However, XML is not a technology to replace HTML, and the existence of both is very important.

XML is a scalable markup language that is customized and designed to contain and transmit data. W3C (Internet management organization) Recommendation standards.

 

Main Applications of XML:1. As the System Configuration File
2. Data Transmission in AjAx
3. Data Transmission in Web Server
4. Data exchange and integration on Heterogeneous Platforms

 

XML isExtensible Markup Language. To better understand XML, Let's first look at the relationship between XML and HTML.

Differences between XML and HTML: 1. XML is not a technology used to replace HTML.
2. XML and HTML are designed for different purposes
3. The core of XML design is data transmission.
4. The core of HTML design is to display data.

 

DTD: Document Type Definition

It defines the legal building module of the XML document. It uses a series of legal elements to define the document structure.

DTD Purpose:1. define the structure of the XML file
2. Provide syntax and rules for XML files
3. The content can be defined in an XML file or outside the XML file.
4. industries or organizations that use XML files for data exchange can define their own DTD.
5. DTD is optional for XML

 

Why use DTD?

The structure to be determined in XML for correct data exchange.

Differences between Schema and DTD:

SchemashiDTD's successor; it will replace DTD in the future

  Schema Advantages:

The Schema can be expanded to meet future needs. The Schema is more comprehensive and powerful; the Schema is written based on XML; and the Schema supports data types.

XML syntax is stricter than HTML Syntax:

NOTE 1: The start and end Tags match.

NOTE 2: Nested labels cannot be nested.

NOTE 3: Case Sensitive

Note 4: an XML file can have only one top-level element.

CDATA :

When we want to output symbols such as >,<, "", '', and so on, they will always go wrong and cannot be lost. CADTA and s are used to make them output as they are and display them as they are.

<Computer books> <bookname <! [CDATA [Oracle application <>>>>>>>>> '''''''''''''""""""""" "" All]> </bookname> <price> 39.00 </price> </computer books>

Summary: XML can be widely used anywhere on the web to meet network application requirements, making programming easier. The code is clear and easy to read and understand.