No output being shown on Mobile Screen in Android studio

Issue

I am trying to run an app with the code on my android studio there is no error the app runs on the device doesn't show output I have shared a screenshot of it

Solution

It seems you're not Overriding the onCreate method. Try this:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.relative_layout);

Answered By - Hamed