std::cout not printing the value with out endl (newline specifier)

Question

Below is my c++ program to multiply two strings (Integers in strings) and produce the integer result in string. I believe it is due to cout flush problem. Can someone explai

Answer 1

You should notice that std::endl includes flushing the output stream. As from the reference documentation:

Inserts a newline character into the output sequence os and flushes it as if by calling os.put(os.widen('\n')) followed by os.flush().

So if you flush cout after printing in your example

cout << multiply("0", "0");
cout.put(cout.widen('\n'));
cout.flush();

you would see the result printed Live Demo.

For more information about flushing and what it actually means for buffered output read here please std::ostream::flush().