Thread: using a for loop to initialize an array

I can't seem to figure this out. How can I use a for loop to accomplish the following?

Code:

classAverage[0] =
	(stuArray[0].grade[0] +
	 stuArray[1].grade[0] +
	 stuArray[2].grade[0] +
	 stuArray[3].grade[0])/4;
	classAverage[1] =
	(stuArray[0].grade[1] +
	 stuArray[1].grade[1] +
	 stuArray[2].grade[1] +
	 stuArray[3].grade[1])/4;
	classAverage[2] =
	(stuArray[0].grade[2] +
	 stuArray[1].grade[2] +
	 stuArray[2].grade[2] +
	 stuArray[3].grade[2])/4;
	classAverage[3] =
	(stuArray[0].average +
	 stuArray[1].average +
	 stuArray[2].average +
	 stuArray[3].average)/4;

You don't. You use two for loops (one for the slow-changing indices, one for the fast).

Originally Posted by tabstop

You don't. You use two for loops (one for the slow-changing indices, one for the fast).

Ahh ha!! Thanks!!! This worked for me...

Code:

int i;
	int j;

	for (i = 0; i < sizeof(stuArray); i++)
	{
	
		for (j = 0; j < sizeof(stuArray); j++)
			
			(stuArray[i].grade[j] +
			 stuArray[i].grade[j] +
			 stuArray[i].grade[j] +
			stuArray[i].average)/4;
	}

Really? I'm assuming you've left bits out, then, and changed some other bits.

Originally Posted by tabstop

Really? I'm assuming you've left bits out, then, and changed some other bits.

LOL! I spoke too soon. I had forgot to comment out my old code. Uhhg!

I'm getting a syntax error saying "invalid operands to binary +"

Code:

       float classAverage[4];
	int i;
	int j;

	for (i = 0; i < sizeof(stuArray); i++)
	{
	
		for (j = 0; j < sizeof(stuArray); j++)
		{
			classAverage = classAverage +
			(stuArray[i].grade[j] + 
			 stuArray[i].grade[j] + 
			 stuArray[i].grade[j] +
			 stuArray[i].average)/4;
		}
	}

stuArray[i].average is what? (I'm guessing that's the + that's being complained about.)

Not that it matters, since it shouldn't be there in the first place, of course.

Originally Posted by tabstop

stuArray[i].average is what? (I'm guessing that's the + that's being complained about.)

Not that it matters, since it shouldn't be there in the first place, of course.

it is supposed to average all the grades of each stuArray[i].grade.

Maybe the rest of the code would help clarify things.
http://www.box.net/shared/vtcg3h2mek