Are the C formatted I/O functions (printf, sprintf, etc) more popular than IOStream, and if so, why? [closed]

Question

I've been looking through a lot of code made by others lately and happened to notice everyone uses "printf" style C functions a lot, but the C++ functions learned in school (cout, specifically) don't seem so popular.

Is this a valid observation, and is there a reason for this? Convention?

Thanks,

R

Answer 1

Personally, I use printf over the iostream stuff (like cout) because I think it's clearer.

When you do formatting with iostream, you have to << all sorts of weirdness like setiosflags and setf. I can never remember which namespace all this stuff lives in, let alone what it all does. Even when I do, I'm disappointed with how verbose and unintuitive the code looks.

The formatting options with printf may seem illegible at first, but they're concise, clearly documented in a single manual page, and common to a wide range of languages.

Another advanage is that printf is stateless: Unlike with cout, I don't need to remember which member functions have been called on printf, or which byzantine concoction of flags has been <<'ed into it. This is a big plus for readability.

Answer 2

I think taste is one possible reason. Personally I find this:

printf("%8d: %s\n", customer->id, customer->name);

more readable than this:

std::cout << customer->id << ": " << customer->name << std::endl;

There's also the issue with localization. printf makes it possible to change the formatting to suit other languages and UI cultures, which becomes a major chore with iostreams, unless you use something like the Boost Format library.