Static variables in C++ and Java

Question

I have a question: let\'s say we have this function: (in C++)

int& f() {
    static int x = 0;
    return x;
} // OK

and

i         


        

Answer 1

Static keyword is used for almost same purpose in both C++ and Java. There are some differences though.

1) Static Data Members: Like C++, static data members in Java are class members and shared among all objects.

2) Static Member Methods: Like C++, methods declared as static are class members and have following restrictions:

• (i) They can only call other static methods.
• (ii) They must only access static data.
• (iii) They cannot access this or super

Like C++, static data members and static methods can be accessed without creating an object. They can be accessed using class name.

3) Static Block: Unlike C++, Java supports a special block, called static block (also called static clause) which can be used for static initialization of a class. This code inside static block is executed only once (first time you make an object of that class or the first time you access a static member of that class (even if you never make an object of that class)).

4) Static Local Variables: Unlike C++, Java doesn’t support static local variables. If used , Java program fails in compilation.

5) Static class: Classes can also be made static in Java.In java, we can’t make Top level class static. Only nested classes can be static.

• Nested static class doesn’t need reference of Outer class, but Non-static nested class or Inner class requires Outer class reference.

• Inner class(or non-static nested class) can access both static and non-static members of Outer class. A static class cannot access non-static members of the Outer class. It can access only static members of Outer class.

  Ref : www.geeksforgeeks.org