Programming Forums > Application Development > C++

ARTillery · Oct 4th, 2005, 7:04 PM

thank you very much for your help..I really appreciate it.

well the code doesn't change much since the last time I wrote it..just changed the name of the function as I told u..here it is..

(Toggle Plain Text)

#include <cstdlib>
#include <iostream>
#include <ctime>

using namespace std;

//function declarations
int main(void);
void ini(void);
int menu(void);
int race(int, int);
int moneybet(int);
void nullrace(void);

int money=200;

int main(void)
{
    ini();
    
    int user_response;
    
    cout<<"welcome to snail races"<<endl;
    while(user_response=menu())
    {
        switch(user_response)
            {
            case 1:
            case 2:
            case 3:
                 ::money += race(moneybet(user_response), user_response);
                 break;
            case 4:nullrace();
                 break; 
            }                          
    }
    return 0;     
}

void ini(void)
     {
         srand(time(0)); 
     }
     
int menu(void)
    {
              int user_choice;
              
              cout<<"you have "<<money<<" dollars to bet with.\n";
              
              do
              {
              cout<<"which snail are u going to bet on?"<<endl
                    <<"[1]snail 1\n"
                    <<"[2]snail 2\n"
                    <<"[3]snail 3\n"
                    <<"[4]just watch\n"
                    <<"[0]exit races\n";
                    
                    cin>>user_choice;
              }
              while (user_choice>0 && user_choice<5);
              return user_choice;                      
    }
    
int race(int money, int user_response)
{

    int winner= rand() % 3 + 1 ;
    cout<<"here goes the race"
           "the winner is the snail number "<<winner<<endl;
           
           if (winner == user_response)
           {
               cout<<"you win "<<money * 2<<" dollars"  ;
               return money *2;        
           }
           else
           cout<<"you have lost your money"<<endl;
           return -1* money;     
}

int moneybet(int userResponse)
{
     int betAmount;
     cout<< "Snail " << userResponse << " is a good choice!"
          << endl;
     cout<< "How much would you like to bet on your snail "
          << userResponse <<"?";
     cin >> betAmount;
     return betAmount;
}


void nullrace (void)
{
    return (0, 0);
}

#include <cstdlib>
#include <iostream>
#include <ctime>

using namespace std;

//function declarations
int main(void);
void ini(void);
int menu(void);
int race(int, int);
int moneybet(int);
void nullrace(void);

int money=200;

int main(void)
{
    ini();
    
    int user_response;
    
    cout<<"welcome to snail races"<<endl;
    while(user_response=menu())
    {
        switch(user_response)
            {
            case 1:
            case 2:
            case 3:
                 ::money += race(moneybet(user_response), user_response);
                 break;
            case 4:nullrace();
                 break; 
            }                          
    }
    return 0;     
}

void ini(void)
     {
         srand(time(0)); 
     }
     
int menu(void)
    {
              int user_choice;
              
              cout<<"you have "<<money<<" dollars to bet with.\n";
              
              do
              {
              cout<<"which snail are u going to bet on?"<<endl
                    <<"[1]snail 1\n"
                    <<"[2]snail 2\n"
                    <<"[3]snail 3\n"
                    <<"[4]just watch\n"
                    <<"[0]exit races\n";
                    
                    cin>>user_choice;
              }
              while (user_choice>0 && user_choice<5);
              return user_choice;                      
    }
    
int race(int money, int user_response)
{

    int winner= rand() % 3 + 1 ;
    cout<<"here goes the race"
           "the winner is the snail number "<<winner<<endl;
           
           if (winner == user_response)
           {
               cout<<"you win "<<money * 2<<" dollars"  ;
               return money *2;        
           }
           else
           cout<<"you have lost your money"<<endl;
           return -1* money;     
}

int moneybet(int userResponse)
{
     int betAmount;
     cout<< "Snail " << userResponse << " is a good choice!"
          << endl;
     cout<< "How much would you like to bet on your snail "
          << userResponse <<"?";
     cin >> betAmount;
     return betAmount;
}


void nullrace (void)
{
    return (0, 0);
}

p.s. I don't know if this might help but the code that I wrote in the first post is my reference and has some comments to help understand what's going on and it's working.

DaWei · Oct 4th, 2005, 7:15 PM

Okay, I ripped it. I won't mess with it tonight, check sometime tamale.

ARTillery · Oct 4th, 2005, 7:18 PM

oh it's fine with me..take your time..and thanks again

Silvanus · Oct 4th, 2005, 8:06 PM

I think the problem is here:

(Toggle Plain Text)

void nullrace (void)
{
    return (0, 0);
}

You're defining the function to return nothing, then telling it to return something. Want you want, I think, is:

(Toggle Plain Text)

void nullrace (void)
{
     race(0, 0);
}

This is what the author's code had.

I'm not really a C/C++ guy, so I might be totally off the mark- but this makes sense to me.

stevengs · Oct 4th, 2005, 8:07 PM

(Toggle Plain Text)

void nullrace (void)
{
    return (0, 0);
}

your prototype says void nullrace(void); The bold void means it promises to return void, which is NOTHING!. But there, within the function definition, what do you see? return (0, 0); This is trying to return something. Even a zero (or whatever that is your are trying to return) is something. You must return void, which means ABSOLUTELY NOTHING. Best bet is to not even have a return statement. (ok, maybe the best thing would be: "return;"):

(Toggle Plain Text)

void nullrace(void)
{
  // Do some stuph, race some snails, show some results, 
  //  BUT DO NOT RETURN ANYTHING!!

  return;
}

You might want to consider getting a different book, or reading some introduction material on the internet. You seem to have a few 'knowledge gaps', which might be due to the material you have.

stevengs · Oct 4th, 2005, 8:43 PM

you probably want nullrace to look something like this:

(Toggle Plain Text)

void nullrace(void)
{
   int winner= rand() % 3 + 1 ;
   cout<<"here goes the race"
           "the winner is the snail number "<<winner<<endl;
   return;
}

ARTillery · Oct 4th, 2005, 9:14 PM

well..that really fixed it..altho it worked with the original code.

I confess..I'm a complete beginner and I'm tryng to follow the book..I understand the concept but when I see the author use them it sometimes confuses me..the book name is "C++ for the absolute beginner"..that's me..but it leaps a bit ahead sometimes.

I'm willing t try another sources though..if u guys know a good source for a beginner like me..please tell me about it..till then, I'll stick to the one I have.

bl00dninja · Oct 5th, 2005, 12:56 AM

now that you got it fixed try debugging it for logic errors to remove shit that doesn't make sense. this is a good excercise.

i ran it twice, the first time i bet "201" and lost, giving me $-1. this indicates that i could bet $800,000,000,000 if i wanted although it clearly states i only have 200.

the second time i bet "f". this caused everything to go crazy. check for crappy input.

also, check to see if the number the user put in is too big for your variable type.

DaWei · Oct 5th, 2005, 9:37 AM

You've received some appropriate responses, so this is more in light of a reiteration.

While modularization is generally a Good Thang, and usually contributes to clarity or understanding, this is patently ridiculous:

(Toggle Plain Text)

   ...
   ini ();
   ...


   ...
void ini (void)
{
   srand (time (0));
}

It would be a different story if "ini" contained a number of things, and was used in a number of places. In this instance, you are at least doubling the amount of work the cpu has to do in order to seed the random-number generator. It actually detracts from clarity in that the reader has to chase it down to read ONE LINE that could have been in place of the call.

This statement,

(Toggle Plain Text)

   cin>>user_choice;

requires two things of the program. It requires that it gather input, and it requires that the input BE CONVERTIBLE TO AN INTEGER. Do you have so much control over your user that you can force him/her to enter an integer? I don't think so. Cin does not promise to do what you want. It promises to do what you want, OR TELL YOU IT FAILED. Do you ask it if it succeeded or failed? Most definitely not. Once it fails, it won't work again until you fix it. I realize that you are new, and that newbies make this mistake unthinkingly and from ignorance. You have been advised. Failure to check your returns, hereafter, is not a mistake, but schlocky programming, the sign of an unemployable, rank amateur. You can spend as much or as little code as you wish trying to analyze or pinpoint the cause of failure, but at the least, you must detect it and prevent disastrous things from occurring.

The following has been explained to you in other responses. If this is in the author's work, shitcan the book. If it's your modification, just take the lesson to heart: read what you just wrote with the eyes of the compiler.

(Toggle Plain Text)

void nullrace (void)
{
   return (0, 0);
}

All the following does is keep you in the loop so long as you enter 1-4. No race takes place. Not too terribly exciting. Side note: real people spell "you" out. Get out of your IM mode if you want to appear to be professional.

(Toggle Plain Text)

   do
   {
      cout<<"which snail are u going to bet on?"<<endl
      <<"[1]snail 1\n"
      <<"[2]snail 2\n"
      <<"[3]snail 3\n"
      <<"[4]just watch\n"
      <<"[0]exit races\n";
      cin>>user_choice;
   }
while (user_choice>0 && user_choice<5);

The correct logic would be: while (user_choice<0 ||user_choice>5);
Only cure for this is to learn boolean algebra.

Whether or not you control the amount of money bet more closely is up to you. If you're of a mind to let the player bet on credit, that's your business. Currently, you place no restriction on the amount bet, although you provide an initial "stake" of 200.

stevengs · Oct 5th, 2005, 10:13 AM

That must be the eleventeen-bazillionth time you've had to mention testing input. However simple yet fundamental it is, you must get tired of repeating it. (or do you copy and paste it anymore?

)

( I reckon it only really hurts when you have to mention it to a self acclaimed seasoned programmer )

Oct 4th, 2005, 7:04 PM	#21
ARTillery Newbie Join Date: Sep 2005 Posts: 17 Rep Power: 0	thank you very much for your help..I really appreciate it. well the code doesn't change much since the last time I wrote it..just changed the name of the function as I told u..here it is.. (Toggle Plain Text) #include <cstdlib> #include <iostream> #include <ctime> using namespace std; //function declarations int main(void); void ini(void); int menu(void); int race(int, int); int moneybet(int); void nullrace(void); int money=200; int main(void) { ini(); int user_response; cout<<"welcome to snail races"<<endl; while(user_response=menu()) { switch(user_response) { case 1: case 2: case 3: ::money += race(moneybet(user_response), user_response); break; case 4:nullrace(); break; } } return 0; } void ini(void) { srand(time(0)); } int menu(void) { int user_choice; cout<<"you have "<<money<<" dollars to bet with.\n"; do { cout<<"which snail are u going to bet on?"<<endl <<"[1]snail 1\n" <<"[2]snail 2\n" <<"[3]snail 3\n" <<"[4]just watch\n" <<"[0]exit races\n"; cin>>user_choice; } while (user_choice>0 && user_choice<5); return user_choice; } int race(int money, int user_response) { int winner= rand() % 3 + 1 ; cout<<"here goes the race" "the winner is the snail number "<<winner<<endl; if (winner == user_response) { cout<<"you win "<<money * 2<<" dollars" ; return money 2; } else cout<<"you have lost your money"<<endl; return -1 money; } int moneybet(int userResponse) { int betAmount; cout<< "Snail " << userResponse << " is a good choice!" << endl; cout<< "How much would you like to bet on your snail " << userResponse <<"?"; cin >> betAmount; return betAmount; } void nullrace (void) { return (0, 0); } #include <cstdlib> #include <iostream> #include <ctime> using namespace std; //function declarations int main(void); void ini(void); int menu(void); int race(int, int); int moneybet(int); void nullrace(void); int money=200; int main(void) { ini(); int user_response; cout<<"welcome to snail races"<<endl; while(user_response=menu()) { switch(user_response) { case 1: case 2: case 3: ::money += race(moneybet(user_response), user_response); break; case 4:nullrace(); break; } } return 0; } void ini(void) { srand(time(0)); } int menu(void) { int user_choice; cout<<"you have "<<money<<" dollars to bet with.\n"; do { cout<<"which snail are u going to bet on?"<<endl <<"[1]snail 1\n" <<"[2]snail 2\n" <<"[3]snail 3\n" <<"[4]just watch\n" <<"[0]exit races\n"; cin>>user_choice; } while (user_choice>0 && user_choice<5); return user_choice; } int race(int money, int user_response) { int winner= rand() % 3 + 1 ; cout<<"here goes the race" "the winner is the snail number "<<winner<<endl; if (winner == user_response) { cout<<"you win "<<money * 2<<" dollars" ; return money 2; } else cout<<"you have lost your money"<<endl; return -1 money; } int moneybet(int userResponse) { int betAmount; cout<< "Snail " << userResponse << " is a good choice!" << endl; cout<< "How much would you like to bet on your snail " << userResponse <<"?"; cin >> betAmount; return betAmount; } void nullrace (void) { return (0, 0); } p.s. I don't know if this might help but the code that I wrote in the first post is my reference and has some comments to help understand what's going on and it's working.

Oct 4th, 2005, 7:15 PM	#22
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	Okay, I ripped it. I won't mess with it tonight, check sometime tamale. __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Oct 4th, 2005, 8:06 PM	#24
Silvanus Hobbyist Programmer Join Date: Aug 2005 Location: Hiding from... them... Posts: 110 Rep Power: 4	I think the problem is here: (Toggle Plain Text) void nullrace (void) { return (0, 0); } void nullrace (void) { return (0, 0); } You're defining the function to return nothing, then telling it to return something. Want you want, I think, is: (Toggle Plain Text) void nullrace (void) { race(0, 0); } void nullrace (void) { race(0, 0); } This is what the author's code had. I'm not really a C/C++ guy, so I might be totally off the mark- but this makes sense to me.

Oct 4th, 2005, 8:07 PM	#25
stevengs Professional Programmer Join Date: May 2005 Location: Bad Nauheim, Germany Posts: 436 Rep Power: 4	(Toggle Plain Text) void nullrace (void) { return (0, 0); } void nullrace (void) { return (0, 0); } your prototype says void nullrace(void); The bold void means it promises to return void, which is NOTHING!. But there, within the function definition, what do you see? return (0, 0); This is trying to return something. Even a zero (or whatever that is your are trying to return) is something. You must return void, which means ABSOLUTELY NOTHING. Best bet is to not even have a return statement. (ok, maybe the best thing would be: "return;"): (Toggle Plain Text) void nullrace(void) { // Do some stuph, race some snails, show some results, // BUT DO NOT RETURN ANYTHING!! return; } void nullrace(void) { // Do some stuph, race some snails, show some results, // BUT DO NOT RETURN ANYTHING!! return; } You might want to consider getting a different book, or reading some introduction material on the internet. You seem to have a few 'knowledge gaps', which might be due to the material you have. __________________ -Steven "Is this a piece of your brain?" - Basil Fawlty

Oct 4th, 2005, 8:43 PM	#26
stevengs Professional Programmer Join Date: May 2005 Location: Bad Nauheim, Germany Posts: 436 Rep Power: 4	you probably want nullrace to look something like this: (Toggle Plain Text) void nullrace(void) { int winner= rand() % 3 + 1 ; cout<<"here goes the race" "the winner is the snail number "<<winner<<endl; return; } void nullrace(void) { int winner= rand() % 3 + 1 ; cout<<"here goes the race" "the winner is the snail number "<<winner<<endl; return; } __________________ -Steven "Is this a piece of your brain?" - Basil Fawlty

Oct 4th, 2005, 7:18 PM	#23
ARTillery Newbie Join Date: Sep 2005 Posts: 17 Rep Power: 0	oh it's fine with me..take your time..and thanks again

Oct 4th, 2005, 9:14 PM	#27
ARTillery Newbie Join Date: Sep 2005 Posts: 17 Rep Power: 0	well..that really fixed it..altho it worked with the original code. I confess..I'm a complete beginner and I'm tryng to follow the book..I understand the concept but when I see the author use them it sometimes confuses me..the book name is "C++ for the absolute beginner"..that's me..but it leaps a bit ahead sometimes. I'm willing t try another sources though..if u guys know a good source for a beginner like me..please tell me about it..till then, I'll stick to the one I have.

Oct 5th, 2005, 12:56 AM	#28
bl00dninja Programming Guru Join Date: Oct 2004 Location: namespace std Posts: 1,246 Rep Power: 5	now that you got it fixed try debugging it for logic errors to remove shit that doesn't make sense. this is a good excercise. i ran it twice, the first time i bet "201" and lost, giving me $-1. this indicates that i could bet $800,000,000,000 if i wanted although it clearly states i only have 200. the second time i bet "f". this caused everything to go crazy. check for crappy input. also, check to see if the number the user put in is too big for your variable type. __________________ i put on my robe and wizard hat... Have you ever heard of Plato, Aristotle, Socrates?...Morons.

Oct 5th, 2005, 9:37 AM	#29
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	You've received some appropriate responses, so this is more in light of a reiteration. While modularization is generally a Good Thang, and usually contributes to clarity or understanding, this is patently ridiculous: (Toggle Plain Text) ... ini (); ... ... void ini (void) { srand (time (0)); } ... ini (); ... ... void ini (void) { srand (time (0)); } It would be a different story if "ini" contained a number of things, and was used in a number of places. In this instance, you are at least doubling the amount of work the cpu has to do in order to seed the random-number generator. It actually detracts from clarity in that the reader has to chase it down to read ONE LINE that could have been in place of the call. This statement, (Toggle Plain Text) cin>>user_choice; cin>>user_choice; requires two things of the program. It requires that it gather input, and it requires that the input BE CONVERTIBLE TO AN INTEGER. Do you have so much control over your user that you can force him/her to enter an integer? I don't think so. Cin does not promise to do what you want. It promises to do what you want, OR TELL YOU IT FAILED. Do you ask it if it succeeded or failed? Most definitely not. Once it fails, it won't work again until you fix it. I realize that you are new, and that newbies make this mistake unthinkingly and from ignorance. You have been advised. Failure to check your returns, hereafter, is not a mistake, but schlocky programming, the sign of an unemployable, rank amateur. You can spend as much or as little code as you wish trying to analyze or pinpoint the cause of failure, but at the least, you must detect it and prevent disastrous things from occurring. The following has been explained to you in other responses. If this is in the author's work, shitcan the book. If it's your modification, just take the lesson to heart: read what you just wrote with the eyes of the compiler. (Toggle Plain Text) void nullrace (void) { return (0, 0); } void nullrace (void) { return (0, 0); } All the following does is keep you in the loop so long as you enter 1-4. No race takes place. Not too terribly exciting. Side note: real people spell "you" out. Get out of your IM mode if you want to appear to be professional. (Toggle Plain Text) do { cout<<"which snail are u going to bet on?"<<endl <<"[1]snail 1\n" <<"[2]snail 2\n" <<"[3]snail 3\n" <<"[4]just watch\n" <<"[0]exit races\n"; cin>>user_choice; } while (user_choice>0 && user_choice<5); do { cout<<"which snail are u going to bet on?"<<endl <<"[1]snail 1\n" <<"[2]snail 2\n" <<"[3]snail 3\n" <<"[4]just watch\n" <<"[0]exit races\n"; cin>>user_choice; } while (user_choice>0 && user_choice<5); The correct logic would be: while (user_choice<0 \|\|user_choice>5); Only cure for this is to learn boolean algebra. Whether or not you control the amount of money bet more closely is up to you. If you're of a mind to let the player bet on credit, that's your business. Currently, you place no restriction on the amount bet, although you provide an initial "stake" of 200. __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Oct 5th, 2005, 10:13 AM	#30
stevengs Professional Programmer Join Date: May 2005 Location: Bad Nauheim, Germany Posts: 436 Rep Power: 4	That must be the eleventeen-bazillionth time you've had to mention testing input. However simple yet fundamental it is, you must get tired of repeating it. (or do you copy and paste it anymore? ) ( I reckon it only really hurts when you have to mention it to a self acclaimed seasoned programmer ) __________________ -Steven "Is this a piece of your brain?" - Basil Fawlty

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Programming Forums > Application Development > C++

While statement