Java is often considered an object-oriented language because it supports the four key principles of object-oriented programming: encapsulation, inheritance, polymorphism, and abstraction. However, some argue that Java is not a purely object-oriented language because it also has primitive types, such as int, boolean, and char, which are not objects.
In a purely object-oriented language, everything would be an object, including primitive types. For example, in Smalltalk, which is considered a purely object-oriented language, there are no primitive types; instead, all values are objects. This means that even simple values like integers and characters are objects, and they have methods and attributes just like any other object.
Java, on the other hand, has a special category of primitive types that are not objects. These types are used to represent simple values like integers and characters, and they do not have methods or attributes. While this design decision was made to improve performance, it means that Java is not a purely object-oriented language.
However, it's important to note that Java's support for object-oriented programming is still very robust, and its use of primitive types doesn't detract from its ability to support object-oriented principles.