I am studying Information Security, what language should I learn?
 

I am already pretty proficient in HTML and CSS but know I need to dig in to something a bit more... difficult. I am going through my degree in Information Security now and would like to learn a language in my spare time that would make me a more attractive candidate for an IT security job in a few years. Which one should I pick?

Also, does learning one language make it easier to learn another language? For example, if I learn PHP, does that make C# or SQL or Javascript easier, etc?

THANK YOU SO MUCH for any advice!!

PHP is a good start, because it's easy to learn.
And knowing html/css you can quickly start doing some real website to practice it.
As for IT security, C/C++ would be good, to start learning from the low-level languages. But it will not be easy to switch from PHP to C as it is more difficult to learn/program.
So, since you have a couple of years ahead, my advice is to start from C.
As to SQL, it is declarative language, and it differs a lot from other languages listed above (PHP, C, Javascript etc), so, from this point it doesn't matter what language you start to learn first.

Most procedural languages have copied a lot for C so learning C would give you a good start to understanding other procedural languages. It does mean you need to install a compiler on your computer to be able to run the code you write though.

With regard to object oriented programming both C++ and PHP suffer from having the ability to use them to write procedural code so if you are going to use either to learn OOP then you need to ensure that you actually use the OOP features of the language and not just the procedural ones.

JavaScript has the advantage that it runs in a web browser without needing a separate compiler. From the security viewpoint it has the disadvantage that because it runs in the browser it doesn't actually have access to anything that presents a security issue. The security issues that are JavaScript related involve security holes in code written in a server side language such as PHP.