C ++: std: endl VS \ n

Taken from here and from here , explaining the following:

The '\n' is a character that, called "line break" or "lone feed", is represented by appearing null, but only positions the cursor on a new line to continue writing.

While std::endl is equivalent to: std::cout << "\n" << std::flush .

Their differences are strictly obvious, since calling the \n character only involves concatenating a single string, but using std::endl calls a clean buffer (which answers your question) .

The cases where they can be used, let's try with the code of the first link:

#include <string>
#include <iostream>

int main() {
    std::string s(1, 'x');
    for (int i = 0; i < 1000000; ++i) {    
        std::cout << s << std::endl;
    }
    return 0;
}

With the following configurations:

clang++ -o endl -O3 endl.cpp && time ./endl >rubbish

Throw the following results:

real    0m4.518s
user    0m1.080s
sys     0m3.311s

While the same code only with the escape:

#include <string>
#include <iostream>

int main() {
    std::string s(1, 'x');
    for (int i = 0; i < 1000000; ++i) {
        std::cout << s << '\n';
    }
    return 0;
}

And the same settings:

clang++ -o endl -O3 endl.cpp && time ./endl >rubbish

Produce these results:

real    0m0.263s
user    0m0.236s
sys     0m0.008s  

Response times are much more effective since it does not "require" to clear the buffer.

This, of course, in a hypothetical case where you do not need to clean the output buffer, but as I mentioned above, there is not enough difference between the two, an escape character will always be printed \n for the new line What leaves one last detail: The only difference is performance.

I hope I help you.