thebaj (3) [Avatar] Offline

In listing 3.3, there is code for onRestoreInstanceState:

protected void onRestoreInstanceState(Bundle savedInstanceState) {
if((savedInstanceState != null) &&
savedInstanceState.containsKey(COUNT_KEY)) {
count = savedInstanceState.getInt(COUNT_KEY);

My question is - why is savedInstanceState check for null, and also containment for COUNT_KEY? how could the situation of null or missing key ever be reached?

The onSaveInstanceState method always saves COUNT_KEY if it is called.