abstraction in java program

Question

Why is the output like below?

bike is created

running safely..

gear changed

because we are not calling Bike() method anywhere.

abstract class Bike {
    Bike() {
        System.out.println("bike is created");
    }

    abstract void run();

    void changeGear() {
        System.out.println("gear changed");
    }
}

//Creating a Child class which inherits Abstract class  
class Honda extends Bike {
    void run() {
        System.out.println("running safely..");
    }
}

//Creating a Test class which calls abstract and non-abstract methods  
class TestAbstraction2 {
    public static void main(String args[]) {
        Bike obj = new Honda();
        obj.run();
        obj.changeGear();
    }
}

Answer 1

Honda class is created with Default Constructor

If a class contains no constructor declarations, then a default constructor with no formal parameters and no throws clause is implicitly declared.

 public class Point {
      int x, y;
 }

is equivalent to the declaration:

public class Point {
      int x, y;
      public Point() { super(); }
 }

So Bike() is called every call to new Honda();

Answer 2

In he Bike class, you have a constructor Bike() that prints a statement. So by default, a child class build upon the constructor of its parent class. That's why when ever you create an object of the class Bike, the print statement has to appear.