has_cvar

Arguments

Returns

t if any instance, class or any parent (base) class contains the variable, otherwise nil.

Description

This function checks for the existence of class variables for a class or instance of a class. It searches all parent (base) classes.

Example

This example is based on the class and method developed in method and class_add_cvar. The variable name is preceded by # to prevent evaluation. See Quote Operators for more information.

Gamma> RegPolygon;
#0=(defclass RegPolygon nil [(linethickness . 2) (perimeter . (defun RegPolygon.perimeter (self) (* (@ self sides) (@ self length))))][length sides])
Gamma> polyD;
{RegPolygon (length) (sides)}
Gamma> Square;
(defclass Square RegPolygon [(area . (defun Square.area (self) (sqr (@ self length))))][length (sides . 4)])
Gamma> sqB;
{Square (length) (sides . 4)}
Gamma> has_cvar(RegPolygon, #linethickness);
t
Gamma> has_cvar(polyD, #linethickness);
t
Gamma> has_cvar(Square, #linethickness);
t
Gamma> has_cvar(sqB, #linethickness);
t
Gamma> 
		

See Also

class_add_cvar