RE: C++ Tutorial - While Loops

mjahpi — Thu, 31 Aug 2017 06:55:26 GMT

Hello; I have a concern with your use of "cin.gcount()". I have made a few modifications to your code to illustrate my concern. For consistency and testing , I set the secret number to always be five (5). I have also added a few "cout <<" statements to ensure my guess, also always five (5), is correctly assigned by your statement "cin >> guess;" and to examine the value of "cin.gcount()". it is examined immediately after your "cin >> guess;" statement. here a portion of the modified code. Note: my changes are left justified for clarity.

int main()

{

// Randomly generate a secret number

srand((unsigned int) time(NULL));

int num = (rand() % 10) + 1;

int num_guesses = 3;

// Print out number first (used for debugging purposes, no cheating!)

num = 5;

cout << "Secret num is : " << num << endl;

// Game intro

cout << "I'm thinking of a secret number (1 - 10), can you guess it?" << endl;

for (int i = 0; i < num_guesses; i++)

{

int guess = 0;

// Read in guess

while (guess < 1 || guess > 10)

{

cout << "Guess a number between 1 and 10? ";

cin >> guess;

cout << "cin.gcount is : " << cin.gcount() << endl;

cout << "Guess is : " << guess << endl;

if(cin.gcount() != 1)

{

cout << "in here (!= 1) , cin.gcount is : " << cin.gcount() << endl;

cin.clear();

cin.ignore(numeric_limits<int>::max(), '\n');

}

CONTINUES UNCHANGED

My output:

Secret num is : 5

I'm thinking of a secret number (1 - 10), can you guess it?

Guess a number between 1 and 10? 5 Note: the 5 after the question mark is my input

cin.gcount is : 0

Guess is : 5

in here (!= 1) , cin.gcount is : 0

Correct, my secret number was 5

You can see that despite the correct answer provided "cin.gcount() returns "0" rather than "1" as suggested in your code.

Comments?

Regards, Mark Hache