How to kill an Android activity when leaving it so that it cannot be accessed from the back button?

Question

In an given Android activity, I would like to start a new activity for the user at some point. Once they leave the first activity and arrive at the second, the first activity is stale and I want to remove it completely so it can not be accessed again from the back button.

How is the best way to accomplish this? How do I kill or destroy this activity immediately after the user has launched the new activity?

Answer 1

You just need to call finish()

Intent intent = new Intent(this, NextActivity.class);
startActivity(intent);
finish();

Answer 2

Setting android:noHistory="true" on the activity in your manifest will remove an activity from the stack whenever it is navigated away from. see here

Answer 3

Yes, all you need to do is call finish() in any Activity you would like to close.