<< and >> in C++

Question

I don't quite understand what this means...I'm just learning C++ from my very very very basic Python experience...and so this may be a very stupid question. My question is...say you have your classic "Hello World" program and you have the line:

cout<<"Hello World!"<<endl;

what does the << mean...because I was just looking at using input in C and saw that you'd do something like:

int i;
cin>>i;

and I noticed that it has >> instead of << and I've read that those are bitwise shifts...and I don't exactly understand what those are...but I think it might be different here...Help...Thanks in advance

Answer 1

In Python, you can implement __lshift__ and __rshift__ to do whatever you want. In C++, it is the same - while the classic meaning is bitwise shift right and bitwise shift left, you can make it do whatever you want.

This is probably one of the most blatant violations of "sensible" operator overloading in C++, but that is just how std::ostream and std::istream work. For all of the C++ lovers out there (myself included), I apologize for this strange choice of operators. Just think of it as the direction that the data flows in (cout << foo puts a foo in cout, cin >> foo puts cin in foo), smile and be happy. From a newcomer, it really doesn't make sense, but drink the C++ Kool Aid and you'll be OH YEAH about it. Trust me.