Thread: Problem with extremely beginner exercise

Hi. I am going through beginner exercises on a C++ tutorial. I came across the number guesser, and I was able to make a once-through program very easily. However, when I try to make a "play again" option, I get multiple playtime errors. It plays the first time, but when I guess the number (and for some reason, every time I play the program, that number is 39... is that supposed to happen?), it displays a blank line. Then, whether I input "y" or "n", it briefly displays my "win" output and asks if I want to play again before it automatically exits. I have no idea where to look.

Here is how I set it up:

Code:

#include "stdafx.h"
#include <iostream>
#include <cstdlib>
#include <ctime>


using namespace std;

int main()
{
	srand(time_t(0)); //seed random number generator

	int theNumber = rand() % 100 + 1; //random number between 1 and 100
	int tries = 0;
	int guess;
	char again;

	cout << "Welcome to Guess My Number!\n\n";//Welcome line

	do
	{
		cout << "You have eight tries to guess the number.\nEnter a guess: ";//Rules
		do
		{
			
			cin >> guess;//Player input
						
			if (guess > theNumber)
				cout << "\nToo high! Guess again: ";
			
			if (guess < theNumber)
				cout << "\nToo low! Guess again: ";
			
			++tries;
			
		} while (guess != theNumber,tries <7);//While loop, for wrong guess, and guesses number less than 8
	
		if (guess == theNumber)
		{
			cout << "\n\nYou got it!  You guessed the number in " << tries + 1 << " tries!";//Correct answer
			cout << "\nDo you want to play again (y/n)?";//Play again option
			cin >> again;
		}

		if (tries < 7)
		{
			cout << "\n\nSorry, you took too many tries.";// Wrong answer, too many guesses
			cout << "\nDo you want to play again (y/n)?";//Play again option
			cin >> again;
		}
			
	} while (again == 'y');
return 1;
}

Any help for a total noob will be greatly appreciated.

Code:

srand(static_cast<unsigned int>(time(NULL)));

//You want logical AND
while (guess != theNumber && tries <7) //This is the correct way

While I'm at it, try not to put arbitrary numbers like 7 in your code, make constants

Code:

const int NUM_TRIES = 7;
//...
int main()
{
...
}

One more thing

Code:

//This
if (tries < 7) 
//Should be this
if (tries > 7)

Along with Desolation's suggestion, you should be close

>NULL should never be used. It's an ugly macro where 0 is always a better alternative.

That's an interesting opinion...

>> warning C4244: 'argument' : conversion from 'time_t' to 'unsigned int', possible loss of data
This warning is ok, and srand(time(0)) is what you should use rather than srand(time_t(0)). If you use time_t(0), you are just casting 0 to a time_t type and passing it to srand, which means you are always seeding srand with 0. If you use time(0), you are getting the current time, so each time you run your program you will be using a different seed. That's what you want.

The warning is because time(0) returns a time_t, which is different than unsigned int. You can ignore the warning, or cast the value like this (I think): srand(unsigned(time(0));

Note that there might be some debate whether that is guaranteed to always work, but in practice you should be fine. Feel free to do some searching on the topic if you are interested in the details (eternallyconfuzzled.com has information about the use of rand).

Yes! I got it!
I took your suggestions, and on top of that, I moved most of the variables and constants into the do loop, most important of which was "theNumber", which made it randomize the number to guess each time. That's kind of important I think. I also had to put some manual break in there for reading the number of tries to make it not display the guess again when you went over the limit. There were also a few other small changes that I don't remember the details of.
Here's my final code for those interested:

Code:

// game1.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>
#include <cstdlib>
#include <ctime>


using namespace std;

int main()
{
	srand(static_cast<unsigned int>(time(NULL))); //seed random number generator

	char again;
	
	cout << "Welcome to Guess My Number!";

	do
	{
		const int MAX_TRIES = 7;
		int theNumber = rand() % 100 + 1; //random number between 1 and 100
		int tries = 0, guess;
		std::cin.ignore(1000, '\n');
		
                cout << "\nYou have eight tries to guess the number.\nEnter a guess: ";
		
                do
		{							
			cin >> guess;
			++tries;			

			if (tries > MAX_TRIES)
			{
				break;
			}
			if (guess > theNumber)
			{
				cout << "\nToo high! Guess again: ";
			}
			if (guess < theNumber)
			{
				cout << "\nToo low! Guess again: ";
			}
			
		} while (guess != theNumber && tries <= MAX_TRIES);
	
		if (guess == theNumber)
		{
			cout << "\n\nYou got it!  You guessed the number in " << tries << " tries!";
		}
		if (tries > MAX_TRIES)
		{
			cout << "\n\nSorry, you took too many tries.";
		}
		cout << "\nDo you want to play again (y/n)?";
		cin >> again;
	} while (again == 'y');
return 0;
}

Thanks all for your help. This has made me very happy. Any suggestions on what to work on next?