EXTEND CLASS statement

The EXTEND CLASS statement extends an existing class.

Syntax

EXTEND CLASS name 
[{
    objectName1 [objectCaption1],
    ...
    objectNameM [objectCaptionM]
}] 
[: parent1, ..., parentN];

Description

The EXTEND CLASS statement extends an existing custom class with additional parent classes and new static objects. You can also extend abstract classes by adding parent classes to them.

Parameters

• name

  Class name. A composite ID.

• objectName1, ..., objectNameM

  Names of new static objects of the specified class. Each name is defined by a simple ID. Name values are stored in the System.staticName system property.

• objectCaption1, ..., objectCaptionM

  Captions of new static objects of the specified class. Each caption is a string literal. If the caption is not defined, the name of the static object will be its caption. Caption values are stored in the System.staticCaption system property.

• parent1, ..., parentN

  A list of names of new parent classes. Each name is defined by a composite ID.

Examples

CLASS ABSTRACT Shape;
CLASS Box : Shape;

CLASS Quadrilateral;
EXTEND CLASS Box : Quadrilateral; // Adding inheritance

CLASS ShapeType {
	point 'Dot',
	segment 'Line segment'
}

EXTEND CLASS ShapeType { // Adding a static object
	circle 'Circle'
}