As you see at below I used "-1" as my sentinel value but my program wants the other 6 values i asked for in scanf too. How can i solve this problem? I just want the user to enter -1 and exit my loop. I would greatly appreciate for your help..

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

#define N 100
#define ISIMUZUN 15

  struct student{
  char name[ISIMUZUN];
  char surname[ISIMUZUN];
  int number;
  float final;
  float midterm;
  float hw1;
  float hw2;
  float grade;
  char *letter;
int main(int argc, char *argv[])

  struct student info[N];
  int i=0, total=0,total2=0,j=0;
  double mean=0, stddvt=0, temp=0;
  int studentcounter=0,aacount=0,bacount=0,bbcount=0,cbcount=0,cccount=0,dccount=0,ddcount=0,ffcount=0,vfcount=0;
  float midtotal=0,midavr=0,fintotal=0,finavr=0,hw1total=0,hw1avr=0,hw2total=0,hw2avr=0;

    do{    printf("Please enter student's information with blanks between them\n");

    scanf( "%d %s %s %f %f %f %f", &info[i].number, info[i].name, info[i].surname, &info[i].midterm, &info[i].final, &info[i].hw1, &info[i].hw2   );
    info[i].grade = (info[i].final*0.4)+ (info[i].midterm*0.25)+ (info[i].hw1*0.15) + (info[i].hw2*0.20);
     }while  (info[i].number!=-1);
6 Years
Discussion Span
Last Post by ilkeamasya

Don't request everything in one scanf call. Call scanf for your sentinel value the check the result and then call scanf for the remainder.


Don't request everything in one scanf call. Call scanf for your sentinel value the check the result and then call scanf for the remainder.

But i needed to have all information with blank space. Is there another way to do it as i wanted?

By the way, I can not print letter

char *letter;
if(info[i].grade >= (mean + 1.5*stddvt)){
    info[i].letter= "AA";



code. I thought using as a pointer would be better as you have said but can not print it out. Any idea about that?

Edited by ilkeamasya: n/a


Calling scanf twice does not mean the user has to enter the data on more than one like. There is no implied reading of a new line character at the end of a scanf call.

scanf just requires whitespace between fields which is space, tab, newline, carriage return but it is not at all fussy about which ones it gets.


Thank you very much.. I think now my sentinel value works perfect. Do you have any idea about printing the pointer ?

char *letter;
if(info[i].grade >= (mean + 1.5*stddvt)){
    info[i].letter= "AA";

This code is wrong. When you say char* letter you just have a pointer. For storing data the pointer has to point to some memory. Check out the function malloc

Edited by abhimanipal: n/a


I see. Thanks for your replies. Everything is working in my code as it should. One quick question if i may :

printf("Student Number             Student Name           Grade   Letter\n");
printf("================  ==============================  =====   ======\n");

	printf("%-18d%16s %-14s%7.2f%8s\n",info[i].number,info[i].name,info[i].surname,info[i].grade,info[i].letter);

I want this to look organized -aligned-. I can left align names but since all names have different number of characters the space between the name and the surname varies all the time. How can i align them?

Edited by ilkeamasya: n/a

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