QuizActivity

package com.example.john.geoquiz;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;


public class QuizActivity extends AppCompatActivity {

    private Button mTrueButton;
    private Button mFalseButton;
    private Button mNextButton;
    private TextView mQuestionTextView;

    private TrueFalse[] mQuestionBank = new TrueFalse[] {
            new TrueFalse(R.string.question_ocean, true),
            new TrueFalse(R.string.question_mideast ,false),
            new TrueFalse(R.string.question_africa ,false) ,
            new TrueFalse(R.string.question_americas ,true) ,
            new TrueFalse(R.string.question_asia ,true) ,
    };
    private int mCurrentIndex = 0;

    private void updateQuestion(){
        int question = mQuestionBank[mCurrentIndex].getQuestion();
        mQuestionTextView.setText(question);
    }

    private void checkAnswer (boolean userPressedTrue){
        boolean answerIsTrue = mQuestionBank[mCurrentIndex].isTrueQuestion();
        int messageResId = 0;
        if (userPressedTrue == answerIsTrue) {
            messageResId = R.string.correct_toast;
        }
        else {
            messageResId = R.string.incorrect_toast;
        }
        Toast.makeText(this, messageResId, Toast.LENGTH_SHORT).show();
        }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_quiz);

        mQuestionTextView = (TextView) findViewById(R.id.question_text_view);
       // int question = mQuestionBank[mCurrentIndex].getQuestion();
       // mQuestionTextView.setText(question);

        mTrueButton = (Button)findViewById(R.id.true_button);
        mTrueButton.setOnClickListener(new View.OnClickListener(){
           @Override
            public void onClick(View v){
               /*Toast.makeText(QuizActivity.this ,
                       R.string.incorrect_toast,
                       Toast.LENGTH_SHORT) .show();*/
               checkAnswer(true);
           }
        });
        mFalseButton = (Button)findViewById(R.id.false_button);
        mFalseButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
              /*  Toast.makeText(QuizActivity.this,
                        R.string.correct_toast,
                        Toast.LENGTH_SHORT) .show(); */
                checkAnswer(false);
            }
        });

        mNextButton = (Button) findViewById(R.id.next_button);
        mNextButton.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                mCurrentIndex = (mCurrentIndex +1) % mQuestionBank.length;
             //   int question = mQuestionBank[mCurrentIndex].getQuestion();
             //   mQuestionTextView.setText(question);
                updateQuestion();
            }
        });
        updateQuestion();

        }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_quiz, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}