Grade program

[twinnie]

I have tried to program a grade program but it keeps not printing out correctly
Please help

#include <stdio.h>  //standard library header file

int
 main( void)
{
	int grade;
	printf("Enter score number ");
	scanf("%i", &grade);
	if (grade < 0 || grade > 100)
	{
		printf("not valid");
	} 
	else if  (grade <= 0 && grade>= 59)
	{
		printf("F");
	 }
	else if (grade <= 60 && grade>= 69)
	{
		printf("D");
	}
	 else if  (grade >= 79 && grade<= 70)
	 {
		printf("C");
	 }
	  else if (grade <= 80 && grade>= 89)
	 {
		printf("B");
	 }
	else if (grade <= 90 && grade>= 100)
	{
		printf("A");
	 }
	  return 0;
}

[redhead]

Try:

scanf("%d", &grade);

And change your conditions to somethign usefull..

if  (grade <= 0 && grade>= 59)

How is tha possible ?? a grade which is less than 0 and at teh same time higher than 59 ???
You might want to change your testing conditions to somethign like:

if  (grade >= 0 && grade<= 59)

DO you see the difference now ??

[twinnie]

I did change that but it keeps printing not valid

[toe_cutter]

Try changing this

if (grade < 0 || grade > 100)

to this

if ((grade < 0) || (grade > 100))

Sometimes it is the order of operation, and I'm not sure which gets calculated first? It is always better to seperate.

Toe

[redhead]

then take a look at this:

#include <stdio.h>  //standard library header file

int main( void)
{
  int grade;
  printf("Enter score number ");
  scanf("%i", &grade);
  if (grade < 0 || grade > 100)
    {
      printf("not valid");
    } 
  else if  (grade >= 0 && grade<= 59)
    {
      printf("F");
    }
  else if (grade >= 60 && grade<= 69)
    {
		printf("D");
    }
  else if  (grade <= 79 && grade>= 70)
    {
      printf("C");
    }
  else if (grade >= 80 && grade<= 89)
    {
      printf("B");
    }
  else if (grade >= 90 && grade<= 100)
    {
      printf("A");
    }
  printf("\n");
  return 0;
}

All I did was change your testign conditions from ( <= && => ) to ( >= && =< ) plus I added a newline to be printed, so you'd see the actual grade on it's own line..

And it does work.....

[twinnie]

Hey- Here is the function version. It does not work



#include <stdio.h> //standard library header file

char get_grades( double grade)
{

printf("Enter score number ");
scanf("%i", &grade);
if (grade < 0 || grade > 100)
{
return("not valid");
}
else if (grade >= 90 && grade<= 100)
{
return("A");
}
else if (grade >= 80 && grade<= 89)
{
return("B");
}
else if (grade <= 79 && grade>= 70)
{
return("C");
}
else if (grade >= 60 && grade<= 69)
{
return("D");
}
else if (grade >= 0 && grade<= 59)
{
return("F");
}

}/*Ends Function*/

int main( void)
{


get_grades(grade);
return 0;
}

[Valmont]

Your function returns a char yet your function body returns const char* .

Thus return 'a' .

[twinnie]

return("B");

do you mean it should be

return('B');

[Deliverance]

There's a couple things wrong with your function

1.

return("not valid");

Your function prototype is a char yet you're trying to return a string (char array I guess since it's C). Try just catching the error, and sending a message to stderr, followed by an exit. Other than that, once your function executes, you're not storing the result anywhere. you have to do something like this:

int main(void)
{
int grade; /* note you should have a value in here */
char a;
a = get_grades(grade); /* now we have your grade letter in here */
return 0;
}

The last thing to mention is this:
Remember, whenever you have an expression (if, while, for, else, etc)
it is only necessary to use { } if there is more than 1 statement to be executed for that comparison / expression, otherwise it will treat the next line as its body, either run or not, then go back to the regular program flow. since we're only doing a return call per 'if' comparison, don't bother with the braces.

Anyways, try something like this out for your function version, should work fine

#include <stdio.h> //standard library header file
#include <stdlib.h>

char get_grades( double grade)
{ 
	if (grade < 0 || grade > 100)
	{
		fprintf(stderr,"Unable to process grade...Invalid\n");
		exit(EXIT_FAILURE);
	}
	if (grade >= 90 && grade<= 100)
		return('A');
	else if (grade >= 80 && grade<= 89)
		return('B');
	else if (grade <= 79 && grade>= 70)
		return('C');	
	else if (grade >= 60 && grade<= 69)
		return('D');
	else return('F');
}/*Ends Function*/

int main(void)
{
	int grade;
	char letter;

	printf("Enter your score ");
	scanf("%i", &grade);

	letter = get_grades(grade);
	printf("Your %i%% is equal to a %c \n", grade, letter);
	return 0;
}

[Valmont]

Originally Posted by twinnie

return("B");

do you mean it should be

return('B');

Try it to find out .