True or False Quiz (Need help)

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

#define TRUE 1
#define FALSE 0

typedef struct question_type{
char question[200];
int response;}
question_type;

const struct question_type question_table[4] =
{
{ "Are you happy?", TRUE },
{ "Are you sure?", TRUE },
{ "Did World War 1 end in 1942?", FALSE },
{ "Did World War 2 end in 1942?", TRUE }
};

int main(void)
{
int cnt, score;
int num_questions = 4;
char response;
score = 0;
cnt = 1;

while (cnt < num_questions)
{
printf(question_table[cnt].question);
printf("(Y/N)\n");
cnt++;
scanf("%c", &response);
response = toupper(response);
if ((response == 'Y' && question_table[cnt].response == TRUE)
|| (response == 'N' && question_table[cnt].response == FALSE))
{
printf("Correct\n");
score++;
response = 0;
}else{
printf("Wrong answer.\n");
response = 0;
}
}
printf("You got %d out of %d questions (%d %%)\n", score, num_questions,
100*score/num_questions);
return 0;
}

That is what I have so far. When you compile it, and enter the answer it doesn't recongize Y or N, then it will jump 2 questions and go to the last one. I've messed around with it now for a week and haven't been able to come up with an answer. If you could tell me what i'm doing wrong and what line to make changes I would greatly appretiate it. Also ignore the questions in there, they are just for now. :)

--Twigg

Add this line as shown

Code:

---

scanf("%c", &response);
while ( getchar() != '\n' );  // add this

---

I think you need to clear the buffer for the keyboard

i.e

fflush(stdin);

> fflush(stdin);
Right idea - wrong way of doing it

Thanks, that stopped the skipping of questions. Now the problem is when I enter y for the first question, it says its correct like its supposed to. Then when I enter the right answer for the next questions it says its wrong. Maybe I need to reset response to something?


--Twigg

> cnt = 1;
Are you sure?
You seem to be starting with the 2nd question.

> scanf("%c", &response);
Try following it with this line
printf( "response=%d\n", response );

This will print the decimal value of the char you read.

If it isn't one of
N=78 Y=89 n=110 y=121
you know where to start looking

uhh.. cnt should start at 0 not 1
because you're skipping the first question when it starts at 1

anyway, a minor note (:

Ian

Well i've checked out the input/output part, and its sending it correctly. I'm really not sure why its not working. Heres an updated version of the changes i made. Anything after the first question, the answer is opposite of what it should be.

Quote:

---

#include <stdio.h>
#include <ctype.h>
#define TRUE 1
#define FALSE 0



typedef struct question_type
{
char question[200];
int response;
}
question_type;


const struct question_type question_table[10] =
{
{ "Are you happy?", TRUE },
{ "Are you sure?", TRUE },
{ "Did World War 1 end in 1942?", FALSE },
{ "Did World War 2 end in 1942?", TRUE }
};

int main(void)
{
int cnt, score;
int num_questions = 4;
char response;
score = 0;
cnt = 0;

while (cnt < 4)
{
printf(question_table[cnt].question);
printf("(Y/N)\n");
cnt++;
scanf("%c", &response);
while ( getchar() != '\n' );
response = toupper(response);
if ((response == 'Y' && question_table[cnt].response == TRUE)
|| (response == 'N' && question_table[cnt].response == FALSE))
{
printf("Correct\n");
score++;
}else{
printf("Wrong answer.\n");
}
}
printf("You got %d out of %d questions (%d %%)\n", score, num_questions,
100*score/num_questions);
return 0;
}

---

1) WW2 ended in 1942??? Funny, as apparently the US fought for 3 more years for no reason, then.

Your problem is that you increment cnt partway through the loop, so it reads the question, increments, and compares the answer to the NEXT question's answer.

So, move cnt++ to the end of the while loop, and all will be good.

To prevent this, you should probably just make the while loop a FOR loop --

for (cnt = 0; cnt < 4; cnt++)

and remove the cnt++ from the loop.

Quote:

---

Originally posted by task
I think you need to clear the buffer for the keyboard

i.e

fflush(stdin);

---

fflush'ing an input stream is not allowed .