Android : When do we use getIntent()?

Question

I dont' understand why we use method getIntent().

Because, when we need that method, We can use method onActivityResult().

But by using the method getIntent(), it could cause NullPointerException.

Answer 1

http://developer.android.com/reference/android/app/Activity.html#getIntent()

Return the intent that started this activity.

If you start an Activity with some data, for example by doing

Intent intent = new Intent(context, SomeActivity.class);
intent.putExtra("someKey", someData);

you can retrieve this data using getIntent in the new activity:

Intent intent = getIntent();
intent.getExtra("someKey") ...

So, it's not for handling returning data from an Activity, like onActivityResult, but it's for passing data to a new Activity.