Structures by reference

[BIGDENIRO]

As usual I'm trapped at something and making slow progress, so here I am again. My problem is that I'm trying to sort and print structures by reference, I think the sorting part is done correctly but the printing is when I see the crash happening.

void printing(struct student *vStudnt, int *sort, char *order){
	int pass;
	int x;
	
	switch(*sort)
	{
		case 1:
			if(*order = 'a' || 'A')
			{
				for(pass = 0; pass < 500; pass++)
				{
					for(x = 0; x < 500; x++)
					{
						if(sorting->lastName[x] > sorting->lastName[x+1])
						{
							temp = sorting[x];
							sorting[x] = sorting[x+1];
							sorting[x+1] = temp;
						}
					}
				}
			}
			else
			{
				for(pass = 0; pass < 500; pass++)
				{
					for(x = 0; x < 500; x++)
					{
						if(sorting->lastName[x] < sorting->lastName[x+1])
						{
							temp = sorting[x];
							sorting[x] = sorting[x+1];
							sorting[x+1] = temp;
						}
					}
				}
			}
			printf("\n%s%s%0d%s%s\n", "Last Name", "First Name", "Age", "Gender", "Class");
			for(x = 0; x < 500; x++)
			{
				printf("%d\n", x);
				*vStudnt = sorting[x];
				printf("%s%s%d%s%s\n", vStudnt->lastName, vStudnt->firstName, vStudnt->age, vStudnt->gender, vStudnt->Class);
			}
			break;

PS: I'm very very bad with pointer.

so can any point out my error?

[laserlight]

You do not seem to have defined the variable named sorting. Furthermore, the only use for vStudnt is to copy sorting[x], which means that vStudnt was completely unnecessary to begin with since you could have written sorting[x].lastName instead of vStudnt->lastName.

By the way *order = 'a' || 'A' is probably a mistake. You might have wanted: *order == 'a' || *order == 'A'

[Matticus]

I don't see where "temp" or "sorting[]" are declared.

for(pass = 0; pass < 500; pass++)
{
    for(x = 0; x < 500; x++)
    {
        if(sorting->lastName[x] > sorting->lastName[x+1])
        {
            temp = sorting[x];
            sorting[x] = sorting[x+1];
            sorting[x+1] = temp;
        }
    }
}

I would suggest not using "magic numbers".

Assuming the "sorting" array is designed to hold that number (500) of elements, you're overrunning the bounds of the array during the last iteration with [x+1] (lines 8 and 9 above).

Bubble Sort and Modified Bubble Sort - Cprogramming.com

[BIGDENIRO]

Both temp and sorting were declared at the top of my program or was I suppose to do it again in the function?

struct student{
	char fLoc;
	int stdNum;
	char firstName[15];
	char lastName[10];
	int age;
	char gender;
	char address[70];
	char Class[10];
	// struct *mInfo;
}sorting[500], temp;

Ohh and LaserLight, IDK why but when I'm comparing chars in IF statement the == doesn't make it compile.

[laserlight]

Both temp and sorting were declared at the top of my program or was I suppose to do it again in the function?

temp, being presumably "temporary", should be declared in the function where it is used. sorting should probably be declared in the main function (and you probably should give it a better name like students), and then you pass a pointer to its first element around to functions that need to access it.

Ohh and LaserLight, IDK why but when I'm comparing chars in IF statement the == doesn't make it compile.

What did you write and what is the compile error?

[Matticus]

Both temp and sorting were declared at the top of my program or was I suppose to do it again in the function?

Those are called "global variables", and they too should be avoided. variables should ideally be declared within the scope they are needed (in this case, your function).

char lastName[10];

But your loop iterates from "lastname[0]" to "lastname[499]". That is a problem.

Ohh and LaserLight, IDK why but when I'm comparing chars in IF statement the == doesn't make it compile.

That doesn't make sense, you must have been doing something else wrong. Can you create a simple program that illustrates the problem you were seeing?

EDIT: laserlight keeps beating me by a minute

[BIGDENIRO]

my head is running water, all other programs have == and compiled............ but thanks for pointing it out and for the tips