XML by Example

XML has many types of entities, classified according to three criteria:

general or parameter entities, internal or external entities, and parsed or

unparsed entities.

General and Parameter Entities

General entity references can appear anywhere in text or markup. In prac-

tice, general entities are often used as macros, or shorthand for a piece of

text. External general entities can reference images, sound, and other docu-

ments in non-XML format. Listing 3.10 shows how to use a general entity

to replace some text.

Listing 3.10: General Entity

<?xml version=”1.0”?>

<!DOCTYPE address-book [

<!ENTITY jacksmith

‘<entry>

<name><fname>Jack</fname><lname>Smith</lname></name> ...