title: Change textView text in onCreate function
body: <p>Can anyone tell me why am i getting error message <code>java.lang.NullPointerException</code> in following code??</p>
  
  <pre><code>package firstApp.hangman;
  
  import android.app.Activity;
  import android.app.AlertDialog;
  import android.content.DialogInterface;
  import android.os.Bundle;
  import android.widget.TextView;
  
  public class HangmenActivity extends Activity 
  {
      private String word_to_guess;
  
      @Override
      public void onCreate(Bundle savedInstanceState) 
      {
          super.onCreate(savedInstanceState);
          this.set_random_word(); 
          TextView wordToGuess = (TextView) findViewById(R.id.word_to_guess);
          try
          {
              wordToGuess.setText(this.word_to_guess);
          }
          catch(Exception  e)
          {
              AlertDialog alertDialog = new AlertDialog.Builder(this).create();
              alertDialog.setTitle("error");
              alertDialog.setMessage(e.toString());
              alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
                 public void onClick(DialogInterface dialog, int which) {
                    // here you can add functions
                 }
              });
              alertDialog.setIcon(R.drawable.icon);
              alertDialog.show();
          }
  
          setContentView(R.layout.main);
      }
  
      private void set_random_word()
      {
          this.word_to_guess = "abcdef";
      }    
  
  }
  </code></pre>