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Android Build a Self-Destructing Message Android App Adding Users Using Parse.com Error Messages with Dialogs

Posted by David Reidy
David Reidy
Courses Plus Student 2,317 Points

Incorrect "correct" answer

import android.app.Activity; import android.app.AlertDialog; import android.app.AlertDialog.Builder; import android.widget.EditText;

public class GuessNumberActivity extends Activity {

protected EditText mNumberField; protected String mUserInput;

// onCreate() and other code has been omitted

public void makeGuess() {
    // Set mUserInput here!        
    mUserInput = mNumberField.getText().toString();
    // Check to see if the user's number is correct
    boolean isCorrect = GuessEngine.testGuess(mUserInput);
if (isCorrect)
    {
      AlertDialog.Builder builder = new AlertDialog.Builder(GuessNumberActivity.this);
      builder.setTitle("Hooray!");
      builder.setMessage("You did it!");
      AlertDialog dialog = builder.create();
      dialog.show();
    }
}

}

The code above works as a correct answer for the challenges, yet in practice it would fail as mNumberField is never initialised and hence would still be null when used in the mUserInput = mNumberField.getText().toString(); line.

Adding in mNumberField = (EditText)findViewById(R.id.numberField); results in a wrong answer.

2 Answers

Ben Jakuben
STAFF
Ben Jakuben
Treehouse Teacher
Ben Jakuben
Ben Jakuben
Treehouse Teacher

Hi David,

Good observation! Note the comment, though:

// onCreate() and other code has been omitted

Some code from Code Challenges is omitted to keep it easier to navigate and focus on the important parts of the challenge. I'll take a look at making that more clear, though. :-)

David Reidy
PLUS
David Reidy
Courses Plus Student 2,317 Points
David Reidy
David Reidy
Courses Plus Student 2,317 Points

Hi Ben,

Yes, that makes sense, I just didn't think that as I'd declared mNumberField and it wasn't mentioned elsewhere in the supplied code that it would be in the omitted code, but then I hadn't considered the omitted code at all really.

Thanks for getting back to me, I'm quite enjoying the course.

All the best,

David.

Ben Jakuben
Ben Jakuben
Treehouse Teacher
Ben Jakuben
Ben Jakuben
Treehouse Teacher

Glad to hear it! Thanks for the feedback, and thanks for being a Treehouse student! :)