Java learning part-1

Today i learned about the basics of java programming language.
First i saw about class and objects
Class-A blueprint for creating objects. It can contain methods (functions) and fields (variables).
Objects-An instance of a class. It allows access to the class's members (methods and fields).

class A{
 int a;
 public void set(int n){
  a=n;
 }
 public int get(){
  return a;
  }
}
public class Main {
    public static void main(String[] args) {
     A a=new a();
     a.set(5);
     System.out.println("a.get());
     A a2=new A();
     System.out.println(a2.get());
   }
}

Command line arguments:
It is used to pass the arguments by the users while executing the program.

Void:The void keyword specifies that a method should not have a return value.

String[] args - here args can be any name like program,java,main,etc.

Static variable can be accessed by objects if the value assigned in the class.

Access specifier:
There are four types of access specifier they are
1.private
2.public
3.default
4.protected

1.private: Accessible only within the class where it is declared.
2.public: Accessible from any other class.
3.default (no modifier): Accessible only within classes in the same package.
4.protected: Accessible within the same package and by subclasses in other packages.