How to logout / Sign out from WhatsApp Messenger App

WhatsApp does not have a logout mechanism. The application is designed to always be connected so that you receive your messages quickly, even when you are not actively using your phone. This is similar to how SMS works and allows WhatsApp messages to be delivered almost
instantly.

But a small info solve you logout & sign out WhatsApp....

HOW TO LOG-OUT FROM THE
WHATSAPP MESSENGER APP?
Go to Settings > Apps Manager or Mange Apps or Apps> Select
WhatsApp from the list.
Tap on "Clear Data" button.
That's it ! Now you are successfully logged out from the
WhatsApp Messenger App. Now you would like to open a new
WhatsApp account from the same phone, just follow the
above steps.