Loop while ENTER is held down exit when released

[Tom Tobias]

I am trying to write a program that goes through a loop while the user holds down the [ENTER] key and EXIT the loop when the key is no longer depressed.
I got the first part, the loop cycles while the key is depressed but the program just stops when the user no longer holds down the [ENTER] key.
I’m not even sure it’s possible. Thank you!

double a = 0;
  double b = 3.5;
  double c = 0;
  char ch; ;
  cout << "  PRESS ENTER KEY ";
  ch = cin.get();
  while(ch)
  {
     ch = cin.get();
     c = a * b;
     a = a + 0.01;
     cout << "\n  TOTAL = " << c;
 
      if (ch = !cin.get()) // THIS DOESN’T WORK
      {
         break;
      }
  }
  cout << "\n  FINISHED";
  cout << "\n  TOTAL = " << c

[Banfa]

You are correct it is not possible, or at least it is not possible using platform independent functions and classes such as cin.

What exactly do you think this line does ch = cin.get();?
How about if the user has given no input yet?

What do you think this line does if (ch = !cin.get())? Break it part method call by method call, operator by operator.

[Tom Tobias]

Thank you very much for your confirmation.
This is part of a somewhat larger program.
The ch = cin.get(); only gets called when
the user initiates input.

[Banfa]

True to some extent but cin is often buffered so in fact the program only receives the data from the user when the user presses enter. The the program receives it all at once.