While Statements Question

Hello,
I am writing a C++ program that displays a multiple choice question, and then asks the user for the answer. I am posting this because I have a couple questions regarding errors I receive. Below is the code.

- I will use a "do-while" loop, to keep the program running until the user gets the answer correct
- I will use "if" statements to give user clues when they get the answer wrong.
- I use an "if" statement when the user types in an answer not on the list of answers for the question, to let them know that they did not enter a valid answer.

Here is the Code:

Code:

---

// name: quiz.cpp
// author: Kautz
// date: November 9, 2008
// description: Multiple Choice Question

#include <iostream>

int main()
{
        char Color;

do
{
cout << "What Color is the Sky?" << endl;
cout << "A. Blue" << endl;
cout << "B. Green" << endl;
cout << "C. Red" << endl;
cout << "A, B, or C?" << endl;
cin >> Color;
}
while (Color == B );
while (Color == C );

        if (Color == B )
{cout << "Hint: Starts with the letter B" << endl;}
        if (Color == C )
{cout << "Hint: Starts with the letter B" << endl;}
        if (Color != A , B, C )
{cout << "You must enter either A, B, or C" << endl;}
        if (Color == A )
{cout << "Correct!" << endl;}

return 0;
}

---

Here is a list of errors that appear:

Code:

---

quiz.cpp: In function `int main()':
quiz.cpp:21: `B' undeclared (first use this function)
quiz.cpp:21: (Each undeclared identifier is reported only once
quiz.cpp:21: for each function it appears in.)
quiz.cpp:22: `C' undeclared (first use this function)
quiz.cpp:28: `A' undeclared (first use this function)

---

I hope that someone can help me out with why there are errors and what I can do to fix them.
It would be greatly appreciated!
Thank you!

You don't have any variables called A, B, or C. Perhaps you want "B" and "C" instead.

Quote:

---

Originally Posted by tabstop

You don't have any variables called A, B, or C. Perhaps you want "B" and "C" instead.

---

What do you mean?
Where would I put "B" and "C" instead?
I don't understand what you're saying.

B is a variable, called, well, B. You don't declare any variables with that name, so you can't use it.

"B" is a string that consists of the letter B. Since that's what you want, that's what you should use. (As in color == "B", etc.)

Several bugs in there:
- Have a look at how while loops work. This:

Code:

---

do {
/*something1*/
while(a);
while(b);

---

Is identical to:

Code:

---

do {
/*something1*/
while(a);

while(b) {
/* Nothing here, just loop indefinitely*/
}

---

Which you probably don't want.

2. As stated, you can't just type A, B or C in the program. But they aren't strings either, they are supposed to be character constants, so they need to be in single quotes. Eg: 'A', 'B'.
So:

Code:

---

char Color;
if(color == A){}  /* Wrong, A is not defined here (unless we defined it earlier) */
if(color == 'A'){} /* Correct */

---

3. You can't do

Code:

---

if(something != value1,value2,value3)

---

If you really think that, then pick up some really basic book or tutorial on programming...