calling struct class within array

eastmus · 12-31-2008, 07:09 AM

Hello

i have a problem calling the struct class data from inside an array...
error: C2664: 'DrukStudent' : cannot convert parameter 1 from 'int' to 'student'.

Code:

struct student
{
	char naam[25];
	struct datum gebdatum;
	int resultaat;
};

void DrukStudent(struct student s)
{	/* naam en gebdatum (dd/mm/jjjj) afdrukken */
	printf("%-10s",s.naam); 
	DrukDatum(s.gebdatum);
	printf(" %d%%",s.resultaat);
}

double gemiddelde(struct student studentrij[ ], int aantal)
{
	int i;
	double result=0.0;
	printf("\ntest array\n");
	DrukStudent(studentrij[1].resultaat); /* here is the problem */
	return result;
}

void main()
{
	struct student studentrij[20] = {{"Anton",{25,4,1988}, 75},{"Bert",{24,5,1987}, 85},{"Chris",{23,6,1986}, 95},{"Dave",{22,7,1985}, 100}};
	gemiddelde(studentrij,4);
}

My purpose is to calculate with the int resultaat within all these arrays.
And i cant seem to target them.

I do not wish to use any pointers (!!)

I know that my double gemiddelde(struct student studentrij[ ], int aantal) isnt looking like it is supposed to be, but right now i just want to target the class of resultaat and then i can move on.

Thanks and happy new year

Elysia · 12-31-2008, 07:12 AM

DrukStudent expects a Student struct, but you pass an int.
And main shall return int, always.

eastmus · 12-31-2008, 07:29 AM

thanks Elysia, but i cant seem to figure out how to target 85 only.
since

Code:

DrukStudent(studentrij[1]);

will give

Code:

Bert      24/05/1987       85%

I dont need the name and date , but just the last int.

Elysia · 12-31-2008, 07:32 AM

So why are you printing the name and the date inside the function?
Remove those printfs, change the function to take the score only and then just print the score.

eastmus · 12-31-2008, 07:42 AM

Quote:

Originally Posted by Elysia

So why are you printing the name and the date inside the function?
Remove those printfs, change the function to take the score only and then just print the score.

it would work then with

Code:

void DrukStudentGemiddelde(struct student s)
{	/* naam en gebdatum (dd/mm/jjjj) afdrukken */
	printf(" %d",s.resultaat);
}

but my point of learning to use struct was trying to target the score by calling it, without making new functions and structs or arrays etc ...

if there is rly no other way ....

tabstop · 12-31-2008, 07:51 AM

Except what you have is targeting the score by calling it, without any extra structs or arrays. How is it not what you want?

Adak · 12-31-2008, 08:23 AM

If I understand this correctly, I'd use a while loop to move the index array from 20(minus 1, so 19 really), back to the comma. The first number would be your one's column digit, so no problem. Your second number, if present, would need to be X 10 + one's column digit, for your total number.

Or, another way, just let the index decrement back to the comma, then reverse it and read in the digits. If you read in 3 digits, you'll need to do this:

Correct value = digit1 * 100 + digit2 * 10 + digit3

to get the value right.

Code:

i = 19;
while(structArray[i] != ',')  //moving index back to the comma
   --i;

for(j = 0; i < 20; i++)   {
   if(structArray[i] >= 0 && structArray[i] <= 9)  {  
      numberchar[j++] = structArray[i];
   }
}

for(i = j - 1; i < MaxChars (2 or 3); i++)   {
   temp = numberchar + '0';  //elevate char to a number
   if(i = 3)                 //restore it's 10's place, again.
      sum = temp * 100;
   else if(i = 2)
      sum += temp * 10;
   else
      sum += temp;
}

print your sum!

I'm assuming 3 or fewer digits in this sample, and have not run this. It would be my starting place, however.

12-31-2008, 07:09 AM	#1
eastmus Registered User Join Date: Dec 2008 Posts: 7	calling struct class within array Hello i have a problem calling the struct class data from inside an array... error: C2664: 'DrukStudent' : cannot convert parameter 1 from 'int' to 'student'. Code: struct student { char naam[25]; struct datum gebdatum; int resultaat; }; void DrukStudent(struct student s) { /* naam en gebdatum (dd/mm/jjjj) afdrukken / printf("%-10s",s.naam); DrukDatum(s.gebdatum); printf(" %d%%",s.resultaat); } double gemiddelde(struct student studentrij[ ], int aantal) { int i; double result=0.0; printf("\ntest array\n"); DrukStudent(studentrij[1].resultaat); / here is the problem / return result; } void main() { struct student studentrij[20] = {{"Anton",{25,4,1988}, 75},{"Bert",{24,5,1987}, 85},{"Chris",{23,6,1986}, 95},{"Dave",{22,7,1985}, 100}}; gemiddelde(studentrij,4); } My purpose is to calculate with the int resultaat* within all these arrays. And i cant seem to target them. I do not wish to use any pointers (!!) I know that my double gemiddelde(struct student studentrij[ ], int aantal) isnt looking like it is supposed to be, but right now i just want to target the class of resultaat and then i can move on. Thanks and happy new year
eastmus is offline

12-31-2008, 07:29 AM	#3
eastmus Registered User Join Date: Dec 2008 Posts: 7	thanks Elysia, but i cant seem to figure out how to target 85 only. since Code: DrukStudent(studentrij[1]); will give Code: Bert 24/05/1987 85% I dont need the name and date , but just the last int.
eastmus is offline

12-31-2008, 07:51 AM	#6
tabstop and the Hat of Guessing Join Date: Nov 2007 Posts: 8,740	Except what you have is targeting the score by calling it, without any extra structs or arrays. How is it not what you want?
tabstop is offline

12-31-2008, 08:23 AM	#7
Adak Registered User Join Date: Sep 2006 Posts: 2,508	If I understand this correctly, I'd use a while loop to move the index array from 20(minus 1, so 19 really), back to the comma. The first number would be your one's column digit, so no problem. Your second number, if present, would need to be X 10 + one's column digit, for your total number. Or, another way, just let the index decrement back to the comma, then reverse it and read in the digits. If you read in 3 digits, you'll need to do this: Correct value = digit1 * 100 + digit2 * 10 + digit3 to get the value right. Code: i = 19; while(structArray[i] != ',') //moving index back to the comma --i; for(j = 0; i < 20; i++) { if(structArray[i] >= 0 && structArray[i] <= 9) { numberchar[j++] = structArray[i]; } } for(i = j - 1; i < MaxChars (2 or 3); i++) { temp = numberchar + '0'; //elevate char to a number if(i = 3) //restore it's 10's place, again. sum = temp * 100; else if(i = 2) sum += temp * 10; else sum += temp; } print your sum! I'm assuming 3 or fewer digits in this sample, and have not run this. It would be my starting place, however.
Adak is offline

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