What are different OOP concepts that are in C++ but not in Java?

There are three main principles of OOP. These include encapsulation, polymorphism and inheritance.   C++ and JAVA differ in approach to each of the above principles. Encapsulation - JAVA follows encapsulation strictly. Everything has to be written within the boundary of the class. However in C++, one can still define the main( ) method outside a class declaration, which is not possible in JAVA. Polymorphism - C++ supports four different types of polymorphism. They are method overloading, constructor overloading, operator overloading and method overriding. However, you cannot overload operators in JAVA. Inheritance - C++ supports multiple inheritances, which JAVA does not. Still, if the need arises, one can make use of interfaces in JAVA for the same purpose. Besides, JAVA has done away with the concept of friend functions.

1) C++ allows friend classes to access members of a class 2) Java all class methods are virtual. 3) Java does not allow multiple inheritance 4) Java is fully object oriented. (everything apart from basic datatypes are classes)