8.Working with Methods and Encapsulation

Question 1

Consider the following class definition:

public class TestClass{
   public static void main(String[] args){  new TestClass().sayHello(); }   //1
   public static void sayHello(){ System.out.println("Static Hello World"); }  //2
   public void sayHello() { System.out.println("Hello World "); }  //3
}

What will be the result of compiling and running the class?

Answer 1

Compilation error at line 3.

It will say, method sayHello() is already defined.
(it will say at line 3 and not 2, because only in line 3 the compiler realise that method signature already exists in the class, ATTENTION to the line numbers where the exception occurs)

You cannot have two methods with the same signature (name and parameter types) in one class.

Doesn’t matter if they are static or not, methods cannot have the same signature in the same class.

Also, even if you put one sayHello() method in other class which is a subclass of this class, it won’t compile because you cannot override/hide a static method with a non-static method and vice versa.