Android Studio Important Shortcut Keys

Alt+F7                : To find usage of a method or class in whole project
alt+ctrl+L           : Reformat code
shift+f6               : Renaming a variable
ctrl+Y                 : Delete a line
ctrl+D                 : Place cursor on a line and press ctrl+D to create a duplicate line
Ctrl+R             : To find and replace particular keywords or text in a class
Alt+Enter+Enter : To extract a string in a resource

Debugging in Android Studio 
F8 to move to next
F9 to move to next debugging point


Shift+f9       : To run app in debug mode
Shift+f10     : To run app
ctrl+9          : Build project