Is Java a pure object-oriented programming language?

Object-oriented programming (OOP) is a programming paradigm that employs a technique of encapsulating related data and functions into cohesive objects, promoting the reuse of these objects across various programs. Numerous programming languages embrace the principles of object-oriented programming, and for a programming language to be deemed pure Object-Oriented, it must fulfill seven essential qualities. These qualities include:

1. Encapsulation/Data Hiding
2. Inheritance
3. Polymorphism
4. Abstraction
5. All predefined types are objects
6. All operations are performed by sending messages to objects
7. All user defined types are objects.

Java is pure object oriented or not?

There is an ongoing debate regarding whether Java can be considered a purely object-oriented language or not. In truth, Java falls short of being a pure OOP language due to two significant reasons that distinguish it from the ideal.

The first reason lies in the presence of primitive data types within Java. In a truly object-oriented programming language, objects should be the sole entities used for data representation. However, Java includes eight primitive data types, such as char, boolean, byte, short, int, long, float, and double, which are not objects themselves. These primitive types can be directly utilized without the need for object instantiation. For instance, one can assign a value to an integer variable like "int x = 10;" without requiring any object reference. This deviation from pure object-oriented principles compromises the language's purity in this aspect.

The second reason is associated with the usage of the static keyword in Java. In a pure object-oriented language, all operations should be performed through message passing, which involves interactions between objects. However, Java introduces the concept of static variables and methods, which can be accessed directly without the involvement of objects. Essentially, when a class is declared as 'static,' it can be referenced and utilized without the need for an object instance. This deviation from the essence of object-oriented programming detracts from Java's claim to being a purely object-oriented language.

Therefore, despite being an object-oriented programming language, Java does not conform entirely to the ideals of purity in object-oriented programming due to the inclusion of primitive data types and the existence of static variables and methods that can be accessed without the intermediary of objects.

Conclusion

Java is not considered a pure object-oriented programming language due to the presence of primitive data types and the inclusion of static variables and methods that can be accessed without objects.