cout or printf which of the two has a faster execution speed C++?
I have been coding in C++ for a long time. I always wondered which has a faster execution speed printf or cout?
Situation: I am designing an application in C++ and I have certain constraints such as time limit for execution. My application has loads printing commands on the console. So which one would be preferable printf or cout?
Answer
Each has its own overheads. Depending on what you print, either may be faster.
Here are two points that come to mind -
printf() has to parse the "format" string and act upon it, which adds a cost.
cout has a more complex inheritance hierarchy and passes around objects.
In practice, the difference shouldn't matter for all but the weirdest cases. If you think it really matters - measure!
EDIT -
Oh, heck, I don't believe I'm doing this, but for the record, on my very specific test case, with my very specific machine and its very specific load, compiling in Release using MSVC -
Printing 150,000 "Hello, World!"s (without using endl) takes about -
90ms for printf(), 79ms for cout.
Printing 150,000 random doubles takes about -
3450ms for printf(), 3420ms for cout.
(averaged over 10 runs).
The differences are so slim this probably means nothing...