If you are looking for a job in IT industry then you can learn 10 programming languages in 2015.
Java: Used for IoT, enterprise architecture, and cloud computing.
C#: Used to create Windows client applications, XML Web services, distributed components, client-server applications and database applications.
PHP: Used for content management systems including WordPress.
C++: Used for high-volume/high frequency trading.
Python: This is freely available and open for modification and reuse.
C: Used to build software for embedded systems.
SQL: Used in relational database management systems.
Ruby: Used for web programming.
Objectivice ├óÔé¼ÔÇ£C: Used for wiring software for OS X and iOS.