printf
is the C way. It isn't typesafe, but it's fast. It runs on the standard C library. (C++ can do this, but it's not normal.)
cout
is the C++ way. It's typesafe, and is the normal way in C++. It runs on the standard C++ library.
WriteLine
is the .Net way, and thus the C++/CLI way. It runs on the .Net library.
WriteConsole
is the Windows way. It's a raw operating system call, so is fast, but it's hard to use and not portable. Don't use this.
As for comparing the languages, C is a less complicated language (making your code more complicated), but C++ has templates, so they're roughly equivalent in speed, depending on the task. They're normal Win32 applications, which means they're pre-complied to raw machine code, and directly run by the processor. C++/CLI runs atop the .Net framework, which means it's compiled as it's being run by the .Net framework, and it tends to run slower than C or C++.
Take all this with a grain of salt. WriteConsole
can do things the others can't easily do. The .Net framework is amazingly fast at certain things. But in general, use the version associated with your lanugage.