Calling a method of a class without creating object of it

Question

class A{
    String z(){
        System.out.println(\"a\");
        return \"sauarbh\";
    }
}
class B{
    A a;
    A x(){
    return a;   
    }
}
public class runner         


        

Answer 1

Yes without instantiate the class if you want to call the method you should use static key word.

What are you doing here?

You are indirectly try to get instance of A. But this case you will get NullPointerException since you just return only a reference(variable) of A

B b = new B();
A a2=b.x();
a2.z(); // NullPointerException from here

NPE?

class B{
  A a;
  A x(){
   return a;   // you just return the reference 
   // it should be return new A();
  }
 }

For your edit:

Take a look at insert() method. It is creating Person instance.