You can use oclIsTypeOf in an OCL expression to test whether an object has one exact runtime class; use it when your model contains inheritance and a subtype must not match.

Syntax

object.oclIsTypeOf(TypeName)

Part	Meaning
object	The object whose runtime type you want to test. In a class context, this is often self.
TypeName	The class to compare with the object's exact runtime class.
Result	A Boolean value: true or false.

How it works

oclIsTypeOf returns true only when the object is exactly the specified class.

It returns false when the object is an instance of a subclass of the specified class. This is the key difference from oclIsKindOf, which returns true for the specified class and its subclasses.

Example: exact type versus inheritance

Assume this inheritance structure:

Vehicle
└── Car
    └── ElectricCar

For an object whose runtime type is Car:

self.oclIsTypeOf(Car)          -- true
self.oclIsTypeOf(Vehicle)      -- false
self.oclIsTypeOf(ElectricCar)  -- false

For an object whose runtime type is ElectricCar:

self.oclIsTypeOf(ElectricCar)  -- true
self.oclIsTypeOf(Car)          -- false
self.oclIsTypeOf(Vehicle)      -- false

Although ElectricCar inherits from Car, it is not exactly a Car for oclIsTypeOf.

Choose the correct type test

Requirement	Operator	Example for an ElectricCar
Match one exact class only	oclIsTypeOf	self.oclIsTypeOf(Car) returns false.
Match a class and any of its subclasses	oclIsKindOf	self.oclIsKindOf(Car) returns true.

Use case

Use oclIsTypeOf when a rule applies only to objects implemented by one specific class. For example, a condition defined on Vehicle can identify objects that are exactly Car and exclude future specializations such as ElectricCar:

self.oclIsTypeOf(Car)

If the same rule must also apply to ElectricCar and other subclasses of Car, use self.oclIsKindOf(Car) instead.

See also

• Documentation:OCLOperators oclIsKindOf
• Documentation:OCL Boolean Operators
• Documentation:OCL General Operators