Question

In Java, please write a tester code.

Here's my code:

public class Bicycle {

    public int cadence;
public int gear;
  public int speed;

    public Bicycle(int startCadence, int startSpeed, int startGear) {

        gear = startGear;
  cadence = startCadence;
speed = startSpeed;

    }

    public void setCadence(int newValue) {

        cadence = newValue;

    }

    public void setGear(int newValue) {

        gear = newValue;

    }

    public void applyBrake(int decrement) {

        speed -= decrement;

    }

    public void speedUp(int increment) {

        speed += increment;

    }

}

public class MountainBike extends Bicycle {

public int seatHeight;

public MountainBike(int startGear, int startCadence, int startSpeed, int startHeight) {

super(startGear, startCadence, startSpeed);
seatHeight = startHeight;

}

public void setHeight(int newValue) {

seatHeight = newValue;

}

}

Answer 1

1. Bicycle constructor parameter order should be correct
super(startGear, startCadence, startSpeed);   // wrong parameters order
super(startCadence, startSpeed, startGear);   // correct order

2. To retrieve the details of the bike, ideally we should define
separate method in MountainBike class (I've added it)
   public String getInfo() {
       String info = "startGear= " +    gear + "\n";
       info += "startCadence= " +    cadence + "\n";
       info += "startSpeed= " +    speed + "\n";
       info += "startHeight= " +    seatHeight + "\n";  
      
       return info;      
   }

//-------- Tester class BicycleTester.java
public class BicycleTester {
        
        public static void main (String args[]) {
                
                //create object of sub/child class
                MountainBike mb = new MountainBike(1,2,3,4);
                
                System.out.println(mb.getInfo()); //call method of mb
                
                                
                // if we dont want to use getInfo() method then we have to
                //get info using MountainBike object mb, as follows             
                /*
                String  info = "MountainBike info: \n";
                info += "startGear= " +         mb.gear + "\n";
                info += "startCadence= " +      mb.cadence + "\n";
                info += "startSpeed= " +        mb.speed + "\n";
                info += "startHeight= " +       mb.seatHeight + "\n";   
                
                System.out.println(info);
                */
                
        }
}

//-------- end of BicycleTester.java

//-------- Bicycle.java
public class Bicycle {

    public int cadence;
    public int gear;
    public int speed;

    public Bicycle(int startCadence, int startSpeed, int startGear) {

        gear = startGear;
        cadence = startCadence;
        speed = startSpeed;

    }

    public void setCadence(int newValue) {

        cadence = newValue;

    }

    public void setGear(int newValue) {

        gear = newValue;

    }

    public void applyBrake(int decrement) {

        speed -= decrement;

    }

    public void speedUp(int increment) {

        speed += increment;

    }

}

//-------- end of Bicycle.java

//-------- MountainBike.java
public class MountainBike extends Bicycle {

    public int seatHeight;

    public MountainBike(int startGear, int startCadence, int startSpeed, int startHeight) {

        //super(startGear, startCadence, startSpeed);   wrong parameters order
        super(startCadence, startSpeed, startGear);

        seatHeight = startHeight;

    }

    public void setHeight(int newValue) {

        seatHeight = newValue;

    }

    //added this method to get bike details
    public String getInfo() {
        String info = "MountainBike info: \n";
        info += "startGear= " + gear + "\n";
        info += "startCadence= " + cadence + "\n";
        info += "startSpeed= " + speed + "\n";
        info += "startHeight= " + seatHeight + "\n";

        return info;
    }

}

//-------- end of MountainBike.java

Output

Thanks...