Forbids comparison between pointer and integer [closed] - c

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Closed 10 years ago.
struct student
{
char am[7];/* èá íáé*/
float final_grade;
float exam_grade;
float essay_grade;
};
struct student mathites[1];
do{
printf("Dwse A.M.:");
scanf("%s",&mathites[j].am);
} while((mathites[j].am<8120000) || (mathites[j].am>812015));
I saw post like this, but everyone asks about comparison with "==" so the answer is strcmp,
something similar for this case?

Answer 1

something similar for this case?
This one is a little different since you're trying to check if a string is within a range of a numeric value.
A few points first:
struct student mathites[1];
if you're going to declare an array of one you may as well not make it an array.
char am[7];/* èá íáé*/
If the largest value you want to compare against is 7 characters "8120000" then you want your array sized 8 (to include space for the null terminator)
scanf("%s",&mathites[j].am);}
You don't need to use the & operator when getting a string, and you should use a limiter so you don't overflow your string
So taken this into account I'd say the code should be more like:
struct student
{
char am[8];/* èá íáé*/
float final_grade;
float exam_grade;
float essay_grade;
};
struct student mathites;
do {
printf("Dwse A.M.:");
scanf("%7s",mathites.am);}
Now your actual question, you need to convert the string to an number first, then check against the value:
long str_value = strtol(mathites.am, NULL, 10);
}
while((str_value <8120000) || (str_value >812015));