Object Class: _isA

Object Class: _isA

Determines whether an object is a member of a class

Syntax
Details

Syntax

objectName._isA( className, descendent );

Argument Type Use Description

className Character Input specifies the one-, two- or three-level name of a class

descendent Numeric Output returns a value indicating whether the object is a descendent of the specified class: 1 is a descendent, 0 is not a descendent

Argument	Type	Use	Description
className	Character	Input	specifies the one-, two- or three-level name of a class
descendent	Numeric	Output	returns a value indicating whether the object is a descendent of the specified class: 1 is a descendent, 0 is not a descendent

Details

The _isA method determines whether an object is a member of a particular class (or a subclass of a class) by comparing the one-, two-, or three-level class name to the value specified in className (ignoring case). This method returns a value of 1 (true) if the class name or the name of any of its ancestor classes ends in the specified value.

This check is useful if you wish to write generic code that can be invoked on any object but that processes the code in a specific manner if the object is a member of a particular class.

You can specify className as a two-level name to compare the library and catalog for the class and determine whether a class exists in a particular catalog.

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