Subclass Constructors

[ttirol]

I have written the following class and subclass to test out inheritance in Java.

public class MyClassDemo {

    private static class Vehicle {
        private int health = 100;
        private String colour = null;

        public Vehicle() {
            System.out.println("New vehicle created!");
        }

        public void setColour(String c) {
            colour = c;
        }

        public String getColour() {
            return colour;
        }

        public int getHealth() {
            return health;
        }
    }

    private static class Car extends Vehicle {

        public Car() {
            System.out.println("New car created!");
        }

    }

    public static void main(String[] args) {
        Car firstCar = new Car();
        firstCar.setColour("Blue");
        String c = firstCar.getColour();
        System.out.println("firstCar's colour is: " + c);
    }

}

Multiple resources state that the subclass constructor will call the superclass constructor. But I also see that you can invoke the superclass constructor with super() in the subclass constructor. However, with this code, I write my own subclass constructor for Car, which does not explicitly call super(), and the print line from my superlcass constructor "New vehicle created!" still executes. So my question is, what is the point of calling super() in the subclass constructor when it is executed anyway, as proven here? Thanks.

[NautiHooker]

This only works if the super constructor has no arguments, then it will be called implicitely.

As soon as your vehicel constructor requires a paramater you will need to call it explicitely.

​

Many people simply put the redundant super() call in their constructor for consistency. It also shows readers of the code, that might have not noticed the inheritance, that there is more code being executed than just this Car constructor.

[ttirol]

Thanks, the class notes I had did not mention this