CLASS

Define a Class for Object Oriented Programming

Syntax

CLASS <ClassName> [ <FROM, INHERIT> <SuperClass> ]

Arguments

<ClassName> Name of the class to define. By tradition, Harbour classes start with "T" to avoid collisions with user- created classes.

<SuperClass> The Parent class to use for inheritance

Description

CLASS creates a class from which you can create objects. Each Class is defined in a separate .PRG file dedicated to that purpose. You cannot create more than one class in a .PRG. After the CLASS command begins the definition, the DATA elements (also known as instance variables) and METHODS of the class are named.

Classes can inherit from a single , but the chain of inheritance can extend to many levels.

A program uses a Class by calling the Class Constructor, the New() method, to create an object. That object is usually assigned to a variable, which is used to access the DATA elements and methods.

Examples

CLASS TBColumn
DATA Block // Code block to retrieve data for the column
DATA Cargo // User-definable variable
DATA ColorBlock // Code block that determines color of data items
DATA ColSep // Column separator character
DATA DefColor // Array of numeric indexes into the color table
DATA Footing // Column footing
DATA FootSep // Footing separator character
DATA Heading // Column heading
DATA HeadSep // Heading separator character
DATA Width // Column display width
DATA ColPos // Temporary column position on screen
METHOD New() // Constructor
ENDCLASS

Status

Ready

Compliance

CLASS is a Harbour extension.

Platforms

All

See Also