Summary of XML Learning notes (i)

Reprint from the Lonely Wolf the Summary of XML Learning (i)--xml Introduction I. XML concept

Extensible Markup Language, translated over for Extensible Markup Language. XML technology is published by the organization, and it is recommended to follow the XML1.0 specification published by the organization in 2000.

Second, the purpose of learning XML

There is a large number of related data in real life, as shown in Figure 1

　　

Figure-1

How can such data be handed over to the computer? , thefundamental goal of the XML language is to describe (Figure 1) the kind of relational data that often occurs in real life .

In the XML language, it allows the user to customize the label. A label is used to describe a piece of data, a label can be divided into start and end tags, between the opening and closing tags, and other tags can be used to describe other data to achieve the description of the data relationship. For example:

1 <?xml version= "1.0" encoding= "UTF-8"?> 2 < China > 3     < beijing > 4         < Haidian ></Haidian > 5         < Fengtai ></Fengtai > 6     </Beijing > 7     < hunan > 8         < changsha ></Changsha > 9         < Yueyang ></Yueyang >10     </Hunan >11     < Hubei >12             < Wuhan ></Wuhan >13             < Jingzhou ></Jingzhou >14     </Hubei >15 < /China >

Iii. Common Applications of XML

XML technology, in addition to preserving relational data, is often used as a software configuration file to describe the relationship between program modules.

In a software system, in order to improve the flexibility of the system, the module it launches is usually determined by its configuration file, such as a software at startup, it needs to start a, b two modules, and a, b two modules at boot, and the need for A1, A2 and B1, B2 module support, in order to accurately describe the relationship, It is most appropriate to use an XML file at this point.

Summary of XML Learning notes (i)