How does android handle app deletion? What happens to remaining data?

Question

When a user deletes or uninstalls an app (e.g. Snapchat) what happens to the data left behind by snapchat? (e.g. sqlite databases and saved images)

Does the OS automatically handle cleaning those artifacts up?

Also what happens when a user reinstalls a previously uninstalled app? Does android do "data wipe downs between installs to insure a clean slate?"

Answer 1

From my experience, the app cached data (databases, settings, etc) will be remove once the app is installed, unless you back it up in external storage or cloud. The files stored such as images and PDFs should also be retained. Here is a link to data backup in android that might be helpful if you are interested in persistent storage https://developer.android.com/guide/topics/data/backup.html In regards to the reinstall, it depends on how it was coded. But i assume that it wouldn't try to clean the data unless the developer wanted to make sure that there was no previous data.

Answer 2

Uninstall an app
It means the app is removed along with its SharedPreferences and database is also removed but if you have saved something on SDCard then that will not be deleted.You can also say that OS handles the removal of SharedPreferences and database but not any data on SDCard this app has.
Reinstall an app after uninstall
Yes, Android OS wipe downs data between installs to ensure a clean slate install but if the app has something to do with data on SDCard then it may affect the app accordingly.
Updating an app
If you install an existing app even if it's the same or different version then its SharedPreferences or databases will not be affected.Same like when you update an app from play store then your data is not lost.

Answer 3

By uninstalling an app all files in the folder - data/data/your.app.package are deleted but I think other files in SDCard are not deleted.