### oefening 1 ###

### activity_main.xml ###

<androidx.constraintlayout.widget...>

    <TextView
    	...
        
        android:id="@+id/textView1"
      	
      	... />

</androidx.constraintlayout.widget.ConstraintLayout>

### MainActivity.java ###

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

    ...

    String varMessage1 = "Java leer je door oefenen";
    TextView myTextView = (TextView)findViewById(R.id.textView1);
    myTextView.setText(varMessage1);

    ...

}