Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Android Build an Interactive Story App Finishing the User Interface Using a Model in the Presenter

Rares Mosescu
Rares Mosescu
2,001 Points

How do I use custom constructor in another class?

I searched how to use a constructor on another class and it's how I've done. I can't figure out what's the problem...

LandingActivity.java
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class LandingActivity extends AppCompatActivity {

    public Button thrustButton;
    public TextView typeLabel;
    public EditText passengersField;

    public Spaceship spaceship;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_landing);

        thrustButton = (Button)findViewById(R.id.thrustButton);
        typeLabel = (TextView)findViewById(R.id.typeTextView);
        passengersField = (EditText)findViewById(R.id.passengersEditText);

        // Add your code here!
        spaceship = new Spaceship(shipType);

    }
}
Spaceship.java
public class Spaceship {
    private String shipType;
    private int numPassengers = 0;

    public String getShipType() {
      return shipType;
    }

    public void setShipType(String shipType) {
      this.shipType = shipType;
    }

    public int getNumPassengers() {
      return numPassengers;
    }

    public void setNumPassengers(int numPassengers) {
      this.numPassengers = numPassengers;
    }

    public Spaceship() {
      shipType = "SHUTTLE";
    }

    public Spaceship(String shipType) {
      this.shipType = shipType;
    }
}

1 Answer

Hi there,

You use the customer constructor exactly as you have done. However, the parameter you pass in needs to be of the correct type. The constructor is:

public void setShipType(String shipType) {
  this.shipType = shipType;
}

This parameter is a String. Once you send the string into the constructor, it'll be referenced with the variable name shipType in the instance of the class you just created. But you need to pass a string to the constructor. The challenge asks you to pass in "FIREFLY" - that looks like:

spaceship = new Spaceship("FIREFLY");

I hope that helps,

Steve.

No problem! I hope it made sense. :+1: