How many OOP that I should learn? There are too many language,which is do you prefer among them?

Answer 1

The concept is similar in all of them, except in JavaScript, just choose the one most suitable to your interests, in my case... PHP.

C is not an OOP language.

Answer 2

I like Java and C#, very similar to PHP too.

Answer 3

@Maz is said perfect
for more refer this links
https://softwareengineering.stackexchange.com/questions/229447/is-there-any-difference-learning-oop-on-different-programming-languages
http://javascriptissexy.com/oop-in-javascript-what-you-need-to-know/

Answer 4

we can't tell you which you have to find the ones which suite you best