How to output an integer using TextView methods?

Question

I want to output a random number, which is always in Activity! here is my code where is the problem?

 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_fourth);
    OnClickButtonListener();
    textBox.setText("" + randomInt);


}
double randNumber = Math.random();
int d = (int) (randNumber * 100 );


int randomInt = (int)d * 2;

TextView textBox = (TextView) findViewById(R.id.textView8);

Answer 1

You need to initialize the TextView inside your onCreate () method. Your code will look something like this.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_fourth);
    TextView textBox = (TextView) findViewById(R.id.textView8);
    double randNumber = Math.random();
    int d = (int) (randNumber * 100 );      
    int randomInt = (int)d * 2;
    textBox.setText("" + randomInt);

}

Answer 2

move TextView textBox = (TextView) findViewById(R.id.textView8);to onCreateand aftersetContentView