std::cout output is not showing in the terminal while debuging my C++ program in VS Code

Question

There is no output being displayed in the terminal during the debug process, it is only displayed after the program has finished executing.

This is during the debug process:

This is after the debug process:

Why is this happening, and how can I get the output to appear during debugging at my breakpoint?

Answer 1

This is probably due to buffering. See Is std::cout buffered? (answer: yes it is buffered). You can manually flush cout in two ways:

1. Use the std::flush manipulator:

   std::cout << std::flush;
   

2. Use the std::basic_ostream<CharT,Traits>::flush member function:

   std::cout.flush();
   

As for why the output appears when your program exits, that's because the C++ specification mandates that all open C streams with unwritten buffered data be flushed at program exit. See Is there a guarantee of stdout auto-flush before exit? How does it work?.