When you search for any Android example in Google, always add “Android Studio programmatically” at the end of your query.
Why add studio?
If you search with the query “Facebook login in Android” then Google will also show you examples which are developed with Eclipse. Examples made with Eclipse are useless because it is officially deprecated.
Put studio in your query, and it becomes “Facebook login in Android Studio.”
So adding Android Studio is must and don’t forget it to save your efforts.
Why add programmatically?
If your query is “Scan barcode in Android” then Google will show you some app URLs to play store which helps the user to scan the barcode.
Google doesn’t know that you are looking for source code to implement scan in Android.
Now if your query is “Scan barcode in Android Studio programmatically” then google will show you examples which are developed with android studio and will also remove app URLs of play store.
Thus adding Android Studio programmatically will save your lot of time in searching right tutorial.