My else block will not be executed when my if condition evaluates to false

Question

This is the first code I have tried to run I have everything working but can't seem to get my "else" statement to display when I type in random characters after "are you satisfied with this output"

int main ()
{
  int Fahrenheit, Celsius, y, Y;
  cout << "Please enter a tempautre in Fahrenheit: ";
  cin >> Fahrenheit;
  cout << "The tempature you entered is: " << Fahrenheit << ".\n";
  Celsius = (Fahrenheit-32) / 1.8; // tempature conversion formula
  cout << "The tempature in Celsius is: "<< (Celsius) << ".\n";
  cout << "Are you satisified with output: " ;
  cin >> y, Y;
  if ((y, Y == y)  ||  (y, Y ==Y))
  {
    cout << "Thank You";
  }
  else
  {
    cout << "Thanks for your input";
  }  
  return 0;
}

`cin >> y, Y;`, `(y, Y == y)`, and `(y, Y ==Y)` do not do what you seem to be trying to do. — Retired Ninja, Jan 20 '20 at 04:59
I am required to have the if/else statements in my code I have tried many variations of cin >> y, Y;, (y, Y == y), and (y, Y ==Y) with varying results. — Programming Newb, Jan 20 '20 at 05:06
You haven't seen any example of code that looks like `cin >> y, Y;` or `(y, Y == y)` anywhere. I think you're confusing identifiers (variable names) with values (e.g. characters like `'y'` and strings like `"y"`). Also, you need to pay attention to types. There is a list of good books [here](https://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list). — molbdnilo, Jan 20 '20 at 09:27

isocppforbids · Answer 1 · 2020-01-20T11:22:21.003

3

Firstly, it's not correct to write it:

    (y,Y == y)

A boolean expression may only have one variable on each side, like this:

    (y == Y)// or
    (Y == Y)

You can't put two variable separated by a comma (,) in the same side.

Finally, the inclusive or operator (||) means that if one of these two boolean expressions is true,

if ((y, Y == y) || (y, Y ==Y)) // these ones here

the final result is also true. And since Y is always equals to Y

    (y,Y==Y)

your final result will be always true.

Also, I don't understant why y and Y are integers. I think you meant something like that, didn't you?

    char y;
    cout << "Are you satisified with output (y/n): ";
    cin >> y;
    if(y == 'y')
    {
        cout << "Thank you" << endl;
    }
    if(y == 'n')
    {
        cout << "Thanks for input" << endl;
    }

edited Jan 20 '20 at 11:22

answered Jan 20 '20 at 05:49

isocppforbids

389
1
12

On the last part, I think the intention is to take both capital and non-capital `y` as confirmation: `if (y == 'y' || y == 'Y')`. Also, small bug: You require the answer before asking the question (`cin >> y` before `cout << ...`). :) – Frodyne Jan 20 '20 at 08:29
Oh, and there is a build in comma operator, so `(y, Y == y)` does technically make sense in C++. But you are correct that it is used in a nonsensical way here. For reference: https://en.cppreference.com/w/cpp/language/operator_other (Look for *Built-in comma operator*). – Frodyne Jan 20 '20 at 08:35

Sargis Khachatryan · Answer 2 · 2020-01-20T12:24:15.900

Input stream objects can read and interpret input from sequences of characters. But one line each time.

You can't do cin>> y, Y; as std::cin takes only a line, instead you can do it separately.

And also this part is wrong:

if ((y, Y == y)  ||  (y, Y ==Y)){}

instead you should write:

if (input /*which should be char type*/ == 'Y' || input == 'y')

This part is also wrong:

Celsius = (Fahrenheit-32) / 1.8; // temperature conversion formula

Your decimal part is lost, as Celsius is of type int

score 0 · Answer 3 · answered Jan 20 '20 at 12:35

This part of your code doesn't look good :

cin >> y, Y;
  if ((y, Y == y)  ||  (y, Y ==Y)) {cout << "Thank You";
  }
  else
  {
    cout << "Thanks for your input";
  }

To check the user input you can write something like:

char response;
cin >> response;
if( ('y' == response) || ('Y' == response) )
{
    cout << "Thank You" << endl;
}
else
{
    cout << "Thanks for your input" << endl;
}

Also, you must understand the difference between a char and a string(vector of chars). By typing a random string in console, the cin will get only the first character because your input variable is of type char.

My else block will not be executed when my if condition evaluates to false

3 Answers3