Siddharth

Well, I can tell you the general difference between methods and functions. 

methods are functions which works on a particular set of data items, like those written inside a class.

Class functions are known as methods because they work on a set of data members. 

While general functions are not bound with any specific data set, they can work on whatever data you provide to them as input.

Well, you have already answered your question.

Since you know n<<1 is already an optimized version of n*2. So basically if you use this in your code, there wont be any further conversion from n*2 to n<<1. And yes, Compiler may do such optimization but if you already using it in your code before hand, your program will run faster.

Here is the thing, being perfect in C++ is a very vague statement. If you know nothing about it, it's gonna take a while because even the experienced programmer doesn't get C++ that much perfectly.

So you need to ask yourself first, how much you wanna cover up in C++ . What is your long term goal about learning C++? Are you like someone who want to just learn it just so that you are good enough to write code. Or you wanna be someone who knows all the pit fall of language.

Once you get all your answers straight, there is blog entry posted by me which will tell you about best books to follow in order to start correctly.

Hope this help. Feel free to ask anything about C++. 

Strictly speaking 'No'. Just doing BCA won't make your resume good enough to get the notice of Google.

The only way it is possible with BCA degree is if you are master of problem-solving and algorithm design and you have cleared some Top level Online Coding test like Google Summer Coding  Challenge etc.