How to pass data between Activities in Android?

Consider a scenario after login activity , Sign-out button visible in each activity , now we need to keep session ID available of all activities !!

Solution:

The easiest way to do this would be to pass the session id to the signout activity in the Intent you’re using to
start the activity:

Intent intent = new Intent(getBaseContext(), SignoutActivity.class);
intent.putExtra("EXTRA_SESSION_ID", sessionId);
startActivity(intent);

Access that intent on next activity:

String sessionId = getIntent().getStringExtra("EXTRA_SESSION_ID");