C++ output string without '\n' or endl will output '#' in the end of string

Question

On ubuntu16.04, I use g++ to compile such code:

#include 

int main()
{
    std::cout << \"Hello World!\";
    return 0;
}

Answer 1

It doesn't, it's your bash prompt.

You can reproduce your problem with echo:

# echo "Hello, World!"
Hello, World!
# echo -n "Hello, World!"
Hello, World!#