Is Java 100% object oriented? [closed]

Answer 1

No, Java is not, since it has primitive data types, which are different from objects (they don't have methods, instance variables, etc.). Ruby, on the other hand, is completely OOP. Everything is an object. I can do this:

1.class

And it will return the class of 1 (Fixnum, which is basically a number). You can't do this in Java.

Answer 2

Java clearly is not 100% OO. You can easily program it in a procedural style. Most people do. It's true that the libraries and containers tend not to be as forgiving of this paradigm.

Answer 3

The problem is that object-oriented is not really well defined and can mean a lot of things. This article explains the problem in more detail: http://www.paulgraham.com/reesoo.html

Also, Alan Kay (the inventor of Smalltalk and author(?) of the term "object-oriented") famously said that he hadn't C++ in mind when thought about OOP. So I think this could apply to Java as well.

The language being fully OO (whatever that means) is desirable, because it means better orthogonality, which is a good thing. But given that Java is not very orthogonal anyway in other respects, the small bit of its OO incompleteness probably doesn't matter in practice.

Answer 4

Java is not fully object oriented. I would consider Smalltalk and Eiffel the most popular fully object oriented languages.