very basic C++ program closes after user input for no particular reason?

Question

I just started learning C++ and I wrote this sample program from the text and when I compile and run it, it just closes after the user inputs any number and presses enter.

Answer 1

The program closes because there's nothing more for the program to do. It outputs the final statements really really fast and then reaches return 0 which causes it to exit. You'll want to do something there to pause the program.

On Windows, a basic way to do that is system("pause"); (you will need #include <stdlib.h>)

cin.getline is a more standard way to do it.

Answer 2

The program you posted has an error. I was not able to compile what you posted.

  cout << "Hello Reader.\n"
   << "Welcome to C++.\n"

is not terminated with a semicolon. I added a semicolon and it compiles and runs as you expect.

Edit: Of course, you have to run the program in a terminal that stays open after the program exits, or use cin to wait for more input, or something like that.

Answer 3

Either put another read from cin to wait for the user, or open the Command Prompt yourself and run it there.

Answer 4

Your program ends right after you print out your text. If you want to see anything on the screen you can add a cin right before your return 0 so your program waits for a user response before exiting.

// Wait for user to hit enter
cin >> dummyVar;

return 0;

Answer 5

It closes because the execution reaches return 0; and there is nothing left to do.

If you want the program to wait before closing you could add an something like this:

cout << "Press enter to exit...";
cin  >> someVarThatWontBeUsed;

You could also run the program from the command line instead of running the .exe. It will reach end of execution anyway but the prompt will stay open.

Answer 6

After the user inputs a number, which is saved to numberOfLanguages, it reaches return 0 which returns from the main function and thus the program ends.