A Tiny Example

class HelloObject
{
  // method definition
  void speak()
  {
    System.out.println("Hello from an object!");
  }
}

class HelloTester
{
  public static void main ( String[] args )
  {
    HelloObject anObject = new HelloObject();
    
    anObject.speak();
  }
}

Above is a complete program which includes a class definition. The definition of class HelloObject includes a method but no instance variables.

When the main() method starts it constructs a HelloObject and then invokes its speak() method.

Objects of class HelloObject have no instance variables. The class does have a constructor but it is not explicitly defined in the code (this will be discussed further).