Click or drag to resize

IsInstanceOfUsual Function

X#
Determine if an object inside a USUAL is an instance of a class.

Namespace:  XSharp.RT
Assembly:  XSharp.RT (in XSharp.RT.dll) Version: 2.19
Syntax
 FUNCTION IsInstanceOfUsual(
	uObject AS USUAL,
	symClassName AS STRING
) AS LOGIC
Request Example View Source

Parameters

uObject
Type: Usual
A USUAL type containing the object to check for.
symClassName
Type: String
A symbolic representation of the class.

Return Value

Type: Logic
TRUE if uObject is an instance of symClassName; otherwise, FALSE.
Remarks
IsInstanceOfUsual() is used to determine whether the polymorphic value uObject belongs to a class whose symbol is symClassName.
An instance of an inherited class is also an instance of the super class. However, an instance of a super class is not an instance of any of its inherited classes. IsInstanceOfUsual() is the same as the following: UsualType(uObject) = OBJECT .AND. IsInstanceOf(uObject, symClassName). Thus, it should be used instead of IsInstanceOf() in situations where it is not known whether a variable is an object. IsInstanceOfUsual()() is also similar to CheckInstanceOf() except that it does not generate an error message if the specified object is not an instance of the specified class.
Examples
This example uses IsInstanceOfUsual() to check whether a USUAL variable is an object of a specific class:
X#
1CLASS Cars
2    EXPORT Wheels
3LOCAL uMercedes
4uMercedes := Cars{}
5? IsInstanceOfUsual(uMercedes, #Cars)        // TRUE
See Also