How do I log off from WhatsApp? I'm trying to exit WhatsApp, but it seems that there is no "Log Off" button. Currently, when I want to exit, I turn off my Wi-Fi/cellular data.  

How do I log off from WhatsApp?
after some experiments i think best way is use Force stop button in Application manager
go to Setting &gt; Application manager &gt; WhatsApp and tap Force stop button  

As say Here:


  Android do not kill the apps totally when you exit from it, this button is for close completely the app and remove it from the stack (apps running), also this button free the memory used by the app  


so Thanks to User pacoespinoza  this is what i want to do!