A new update to WhatsApp brings a new feature, now the Android app has received support for quick reply so that you can reply to notifications very easily without even opening the app. This feature is available in the latest beta version 2.12.560 through the Google Play Store, so it is also not available through the website yet.
This feature works even from lock screen or from any other screen. when u click the reply button it brings a pop-up notification so that you can reply quickly instead of opening the app. After replying to message, you can just continue the work you were doing before in your mobile. There is no option to turn off this feature in settings.
WhatsApp is being updated much frequently for a while now, You can also join beta testing for android if you would like to test app before they release for whole public. You can join the here. Follow us on Twitter for more updates.