How to invoke method returning reference type properly?

Question

I was going through the Oracle Java tutorials on the method returning the results of a reference type but had been stuck for quite a few hours. The link is provided here.

https://docs.oracle.com/javase/tutorial/java/javaOO/returnvalue.html

public class Bicycle {

    private int speed = 0;

    public Bicycle(int a) {
        speed = a;
    }

    public static Bicycle seeWhosFastest (Bicycle bicycle1, Bicycle bicycle2) {

        Bicycle fastest = bicycle1;

        if (bicycle1.speed < bicycle2.speed) {
            fastest = bicycle2;
        }

        return fastest;
    }

    public static void main(String[] args) {

        Bicycle firstBicycle = new Bicycle(100);
        Bicycle secondBicycle = new Bicycle(200);

        Bicycle.seeWhosFastest(firstBicycle, secondBicycle);
    }

}

However, I couldn't get it to work as intended. I was hoping to at least print out the bicycle2 object but nothing showed.

Could you guys help me out here thanks in advance.

Answer 1

Considering that your static seeWhosFastest method returns a Bicycle reference type you can write:

public static void main(String[] args) {

        Bicycle firstBicycle = new Bicycle(100);
        Bicycle secondBicycle = new Bicycle(200);
        Bicycle fastestBike = Bicycle.seeWhosFastest(firstBicycle, 
secondBicycle);
        System.out.println(fastestBike);
}

In order for this to print something significant you will need to override the toString method from your Bicycle class with something similar to @Makato's example

EDIT from your comments:

First add a second member variable to your Bicycle class something like:

private String reference;

and then add a toString method (also in your Bicycle class)

public String toString() {
    return reference;
}

Now update your bicycle constructor to something like

public Bicycle(int speed, String reference) {
    this.speed = speed;
    this.reference = reference;
}

Now change your main method as follows:

public static void main(String[] args) {

        Bicycle firstBicycle = new Bicycle(100, "Bicycle1");
        Bicycle secondBicycle = new Bicycle(200, "Bicycle2");
        Bicycle fastestBike = Bicycle.seeWhosFastest(firstBicycle, 
secondBicycle);
        System.out.println(fastestBike);
}

And it should work as expected

Hope this helps