Need help with "if" function

I just started coding in C today, and I haven't been able to figure out what is wrong with this. I am trying to make a "guess the number" game, but I keep getting a syntax error on the "if" line. Could someone please tell me what is wrong with this?

Code:

---

#include <stdio.h>


int main()
{
    int correct;
    correct=13;
{
  int number;
  printf ( "Guess a number: ");
  scanf( "%d", &number );
  return 0;
}
}
if(correct==number)
{
                  printf("You Win!"
                  }
else
{
    printf("You Lose")
}

---

You don't need your second, third or forth curly braces, but you should have one after the else statement.

return 0; should only be at the end of your program - execution will end when it gets to this point.

There's nothing wrong with the if statement itself.

You need closing parentheses and semi colon after "You Win!"

After the else statement?

Code:

---

else
{
    printf("You Lose")
}

---

Why would I need another one? It already has a beginning and end bracket...

Edit: oh, I see what you mean.

Ok, I got it working, but could you tell me how to make the number random every time instead of a constant?

http://www.cprogramming.com/tutorial/random.html

The code in that tutorial is C++, so it's a slightly different syntax in some parts, but the random number part should be the same for C.

i.e. You "seed" it by passing srand some value based on the time, then subsequent calls to rand() return random numbers. Include stdlib.h to use those functions and the RAND_MAX constant.

By using the srand() and rand() functions contained in stdlib.h.

srand() seeds the random number generator with a value. If given the same seed, then rand() will return the same numbers in sequence. Usually, the time is used to seed the random number generator. So, for example:

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main(int argc, char *argv[]) {
    srand(time(NULL));
    printf("A random number: %i\n", rand());
    printf("A random number between 0 and 99: %i\n", rand()%100);
    return 0;
}

---

Stepping through that, well.

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

---

I think you probably know what these are. In this case, stdio.h is used for printf(), stdlib.h for srand() and rand(), time.h for time().

Code:

---

int main(int argc, char *argv[]) {

---

Standard main() function.

Code:

---

    srand(time(NULL));

---

This calls srand() with the current time, as returned by the time() function. If you pass a pointer to time(), it will store the time in that variable. But because it additionally returns the time, you can seed the random number generator directly without using an additional variable.

Code:

---

    printf("A random number: %i\n", rand());
    printf("A random number between 0 and 99: %i\n", rand()%100);

---

The first simply prints out a randomly-generated number from the rand() function. This will be between 0 and (2^31)-1, probably not what you want. So, the second applies a modulus of 100 to the randomly-generated value. Modulus = remainder. Think of it as converting 1234 into 34, removing all but the tens and ones columns of a number. (If you use number%2, it will be 1 if number is odd, 0 if it's even.)

Code:

---

    return 0;
}

---

Terminate with a return code of 0, or success.

EDIT: dang, sean beat me to it :P

Edit: nvm, I got it. Thanks for your help.

Ok, I need help again

Now I am trying to make it so you can choose to try again after you win or lose. I looked in the other thread that was similar, but I can't figure it out. What is wrong with this?:

Code:

---

#include <stdio.h>
#include <conio.h>
#include <ctype.h>
#include <process.h>


int main(int argc, char *argv[])
{
    int guess;
    char choice, y, n, Y, N;
    Y=y;
    N=n;
   
while (choice == y)
{
    printf("Guess a number: ");
    scanf("%i" , &guess);
    srand(time(NULL));
    if(guess==rand()%21)
    printf("\nYou Win!");
    else
    printf("You Lose! My number was: %i" , rand()%21);
                char choice;
        printf("\nWould you like to try again? [Y/N]: \n");
        scanf( "%c" , &choice );
}
}

---

have you already searched the forum?

I found a thread about it, but I still can't figure it out.

Code:

---

char choice = 'n';
do
{
  ...
  scanf("%c ",&choice);
} while(tolower(choice) == 'y');

---

Quote:

---

Originally Posted by wipeout4wh

Code:

---

   
while (choice == y)

---

---

Should that not be (choice == 'y')?

An example program, much like what I think you're trying to do . . .

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>

int main(int argc, char *argv[]) {
    int i, num, tries;
    char cont;
    srand(time(NULL));
   
    do {
        num = (rand()%100)+1;
        i = -1;
        tries = 0;
        while(num != i) {
            if(i != -1) {
                if(i > num) {
                    printf("Too high!\n");
                }
                else printf("Too low!\n");
            }
            printf("Enter a number between 1 and 100: ");
            scanf("%i", &i);
            tries ++;
        }
        printf("Got it in %i %s. Again? [yY/nN] ", tries, tries == 1?"try":"tries");
        while((cont = tolower(getchar())) && cont != 'y' && cont != 'n') ;
    } while(cont == 'y');
   
    return 0;
}

---

Example output:

Code:

---

Enter a number between 1 and 100: 1
Too low!
Enter a number between 1 and 100: 50
Too low!
Enter a number between 1 and 100: 75
Too high!
Enter a number between 1 and 100: 66
Too high!
Enter a number between 1 and 100: 59
Too high!
Enter a number between 1 and 100: 55
Too low!
Enter a number between 1 and 100: 57
Too high!
Enter a number between 1 and 100: 56
Got it in 8 tries. Again? [yY/nN]y
Enter a number between 1 and 100: 50
Too low!
Enter a number between 1 and 100: 75
Too low!
Enter a number between 1 and 100: 88
Too high!
Enter a number between 1 and 100: 81
Too low!
Enter a number between 1 and 100: 84
Too low!
Enter a number between 1 and 100: 86
Too low!
Enter a number between 1 and 100: 87
Got it in 7 tries. Again? [yY/nN]n

---

Quote:

---

Originally Posted by wipeout4wh

Ok, I need help again

Now I am trying to make it so you can choose to try again after you win or lose. I looked in the other thread that was similar, but I can't figure it out. What is wrong with this?:

---

Any characters, such as y needs to be enclosed in single quotes, thus: 'y'.
If you do NOT do this, the compiler thinks it's a variable and it's not, is it?

Furthermore, srand should only be called once during your program.
And you'll want to cast the return of time to avoid compiler warnings:

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

And lastly, you need to look into what indentation is: http://cpwiki.sourceforge.net/Indentation

Quote:

---

Originally Posted by Nightowl

An example program, much like what I think you're trying to do . . .

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>

int main(int argc, char *argv[]) {
    int i, num, tries;
    char cont;
    srand(time(NULL));
   
    do {
        num = (rand()%100)+1;
        i = -1;
        tries = 0;
        while(num != i) {
            if(i != -1) {
                if(i > num) {
                    printf("Too high!\n");
                }
                else printf("Too low!\n");
            }
            printf("Enter a number between 1 and 100: ");
            scanf("%i", &i);
            tries ++;
        }
        printf("Got it in %i %s. Again? [yY/nN] ", tries, tries == 1?"try":"tries");
        while((cont = tolower(getchar())) && cont != 'y' && cont != 'n') ;
    } while(cont == 'y');
   
    return 0;
}

---

---

Ok, thank you. Could you explain this code to me though? Also how would I make it so you don't need to press enter after pressing y or n? If that is too complicated, don't worry about it, since I'm not very good at this yet and probably wouldn't understand.

Is there a specific part of it you don't understand? You've already used or had explained everything in this code, as far as I can tell.

Not having to press enter after entering the character isn't very simple. There are simple ways provided by a lot of compilers let getch() in conio.h, but that isn't standard.

for function u need () and read abt function return and parameters etc anyways here a code it will return 1 if num is 13 then we can l8er chk if its return is 1 on right and 0 on wrong.

Code:

---

#include <stdio.h>
int int_guesser()
{
    int num;
    puts("Guess a num : ");
    scanf("%d",&num);
    if(num==13)
        return 1;
    else
        return 0;
}
int main()
{
    int num;
    num=int_guesser();
    if(num)
        puts("gratz u guessed right");
    else
        puts("Wrong guess try again");
   
  return 0;
}

---

;.

In order to make you not have to press <enter> after entering a char, you would have to look outside the ANSI C library, and into the POSIX C library, I believe. Or just use getch()/getche(). getche() works on the gcc supplied with Dev-C++, getch() on other compilers I believe. Not certain, it's been a while since I did interactive console programming ;)

I'm sorry, I really should have explained in greater depth what I was trying to do. I usually program without comments for programs < 250 lines.

Here's a nice breakdown of how it all fits together . . .

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>

---

The includes. stdio.h for printf(), stdlib.h for srand() and rand(), time.h for time(), and string.h for tolower().

Code:

---

int main(int argc, char *argv[]) {
    int i, num, tries;
    char cont;

---

Main function declaration and variable declarations.

Code:

---

    srand(time(NULL));

---

Seed the random number generator with the current UNIX time in seconds.

Code:

---

   
    do {

---

I'm assuming you've run into do...while loops before. If not, well . . . a do...while loop is much like a while() loop, but instead, do...while loops check the condition at the bottom of the loop rather than the top. This means that they will always run at least once.

Code:

---

        num = (rand()%100)+1;

---

Set the random number to guess for this game. Since rand()%100 returns a number in the range 0-99, you want to add 1 to it to get 1-100.

Code:

---

        i = -1;
        tries = 0;

---

Initialize the variables for the game. i is the entered number, which is set to -1 to indicate that no number has been entered yet. tries is the amount of tries that the player has gone through in order to guess the number, zero at the first round.

Code:

---

        while(num != i) {

---

Loop until the entered number (i) is the same as the randomly-generated number (num).

Code:

---

            if(i != -1) {

---

If this is not the first round . . .

Code:

---

                if(i > num) {
                    printf("Too high!\n");
                }
                else printf("Too low!\n");

---

Compare i to num. Since i will never be equal to num because of the while() loop condition, simply print "Too high!" if the number entered was > the randomly-generated number, else print "Too low!".

Code:

---

            }
            printf("Enter a number between 1 and 100: ");
            scanf("%i", &i);

---

Finish off the if(i !=-1) if block first. Then, print a prompt for the player and retrieve the entered number into the variable i.

Code:

---

            tries ++;

---

Increment the number of tries.

Code:

---

        }

---

Finish off the while(i != num) loop. If it gets past this point, then the number entered was the same as the random number, so . . .

Code:

---

        printf("Got it in %i %s. Again? [yY/nN] ", tries, tries == 1?"try":"tries");

---

This is a little bit of fancy footwork. The %i should be easy enough. The %s, on the other hand . . . Suffice to say that if the condition (tries == 1) is true, then it will print "try", otherwise it'll print "tries". (1 tries doesn't sound too good ;) ).

Code:

---

        while((cont = tolower(getchar())) && cont != 'y' && cont != 'n') ;

---

Again, some fancy footwork. This loop will continue going around until the keyboard buffer is cleared, and until the player enters 'y' or 'n', in either case. The function tolower() converts an uppercase char into a lowercase char, or leaves it alone if it's either a non-alpha char or already lowercase. ;)

Code:

---

    } while(cont == 'y');

---

aaand continue the do...while loop until the user enters 'n', to indicate that they don't want to try playing again.

Code:

---

    return 0;
}

---

Finish up and return 0.

Hope this helps a tad. ;)