agreed i dont work in java, but if he wants to learn these are all probably good starting places.

also C# is fine if you want a C# job. I probably should have said that. My view is it will not be around for the longest time. MS just released typescript (ms varient of nodejs), and most mission critical stuff is done in other languages.

Two examples why I don't write more C#:

Orginally the startmenu/taskbar was going to be written in C#, they scrapped it and went back to C++ b/c performance was so bad. (And I'm assuming plagued with memory leaks).

If you try to play the C# Hearts thats included on Windows7, on a 2ghz machine with onboard video (no d3d acceleration) - its so slow it's completely unplayable. Apparently even the MS-engineers could not make a simple card game work on a non hardware accelerated system.

Guys, please ignore his comment:

1) "typescript (ms varient of nodejs)" - no, it is not. "Project Helios" is Microsoft's Node.js. Typescript is just a way of adding static typing to JavaScript.

2) Unity makes an extensive use of C#, are you saying that e.g. recent Angry Birds franchise games are slow? Are these games slow: https://unity3d.com/showcase/profiles? Are XNA/MonoGame games slow as well?

yes. in my personal experience a C# engine is slower than a good (*) c++ engine.

sorry i got the name wrong on the js part, it was a while back.

C# will be around 'forever'. It's robust, well-supported, well-documented, and with Mono / Xamarin works across many platforms (including iOS and Android). I haven't experienced inherent memory leaks as you have described (10+ years of heavy use). Performance limitations are more tied to IO (disk, network etc) than the language.

That said, this isn't an either/or question. One can learn more than a single language at a time. A decent programmer, IMO, has knowledge of several languages, and there is no disadvantage at all in making one of those C#.