apart from c,c++,java what should i must learn to add to my programming skills

Nowadays I would definately learn some stuff about web frontend.
That way you can develop on a full webstack. (And help out frontenders on your team)

it would be helpful to mention what you wanna work on in the future. Embedded Systems programming? Computer Graphics? Software Development (web/mobile/desktop...)? etc... all these are factors which could help you choose your language of interest.
But in all cases, you need to know basic programming + OOP with a lot of practice. Cheerz

@achehab i wanna be a web and android software developer :)

1. Add Design Patterns & SOLID programming to your java skills.

2. As @ChappIO mentioned, learn a full web stack, e.g: "MEAN stack", & look up "ionic framework". (These are only examples, yet well known).

@Heatstreak Php 😂🔫

@Heatstreak Yeah, you're right. But still...

@mangs what's wrong with php??

Functional programming: Haskell

@Rajat you could get your hands on RoR, I really liked it so far.

try Golang maybe. Very fast pretty low level and very powerfull. If you intrested in web/mobile and wand somthing solid at the back.
and after C++ it will come easy for you..

It depends on what your interested in doing. however, you seem to be something like a third-year undergrad (I know because I am and I have the same questions), and tjhe best advice forbthat period is to get good habits. Get used to writig tests before code, separate reaponsibilities, etc. Any Fowler or Incle Bob talk is good. Technologies come and go, but if you have strong habits and fundamentals you can learn anyting faster end better.

python? hmmm?

You should experience a little bit on android. A scripting language may be a good idea if you want to make scripts to do boring tasks for you. Some computer science concepts if don't have them.
So you can learn : Java for android, Python(for scripting) and Dango for Web.
In computer science comcepts'so you should learn algorithms and data structures and design patterns for object oriented languages like java.

@kerith tests before code? O.o how? I mean they won't run for sure...

SOLID concept, design patterns (for all languages), some PHP, Go, JavaScript, Rest, Unit testing, behavior testing, micro services...

@SirWindfield No, they don't work, but that's great. The thing is that you force yourself to write tests before code, and after write _just enough_ code so thatthe tests pass (like 5 minute cycles of test/code). that way you end up with a very complete test suite that you can pass at amy time, (at the end of the cycle for example) and _know_ that you haven't broken anything. there's much more to that, for more info you can google "TDD" or "Test Driven Development", or kust star with this talk http://m.youtube.com/watch/...

@Rajat
<rant>
for the love of God, if you want to be a web developer, learn JavaScript. Not React. Not angular. Not JQuery. Learn everything about how the language works. This includes functional inheritance (many don't like it, I personally do, either way you have to understand it). Whatever you do, don't be the designer that wants to learn "coding" and just learn one popular framework.
</rant>