Are classes instances?

Question

public class MyClass {
public static int k = 0;
public static void main(String[ ] args) {
k++;
MyClass.k++;
System.out.println(MyClass.k);
// outputs 2
}
}

In the code snippet above, I created a static variable "k" and i used a uninary operator ++ to add one to the variable. In the same variable, i accessed it via MyClass.k and k directly, but what is the difference?

Answer 1

Since you have declared this as static so it can be accessed through class and also it is a global variable so it can be accessed directly in any method of the same class. However if this k variable would have been in another class you can only access it through that class. eg

public class A{
public static int i =0;
}
public class B {

public static void main(String[] args){
A.i++; // will compile
i++; // shows error
System.out.println(A.i);
}
}
output : 1

Answer 2

i don't think there is any difference as far as the memory efficiency is concerned but using k++ is efficient and simple so definitely k++ when you use variable in the same class

Answer 3

yeah ok, but for best practise, should i run MyClass.k to access the static variable in the same class or should k++ be done instead

i understand that from other classes, i would have to use MyClass.k