How do I need to define this?

[rickrets]

Hello,

I'm having trouble finding the solution for the following problem:

I have this piece of code:

int vraagNummers[result.count];
int i;
int j;
int r;

for (i = 0; i < result.count; i++) {
vraagNummers[i] = i;
}

for (i = (result.count - 1); i > 0; i--) {
r = arc4random() % (i + 1);
if (r < i) {
j = vraagNummers[i];
vraagNummers[i] = vraagNummers[r];
vraagNummers[r] = j;
}
}

for (int i = 0; i < 50; i++) {

NSDictionary *stream = (NSDictionary *)[result objectAtIndex:vraagNummers[i]];

--rest of code--

This is giving me the following warning when I build + analyze:

Pass-by-value argument in message expression is undefined

This warning is beneath "..onary *)[result objectAtIndex:vraagNummers[i]];"

Does anyone see what I'm doing wrong here? Can you tell me the solution?

Regards,

Rick

[RLScott]

Originally Posted by rickrets

int vraagNummers[result.count];

This is a problem. A declaration of a C-style array must specify a constant as the number of elements in the array. result.count is not a constant. One solution, if you know for a fact that result.count can never be larger than, say, 100, is to declare int vraagNummers[100];

[rickrets]

--EDIT--

You are right, I had to change every result.count to some int...

Is there no way to get it filled with something changeable??

[rickrets]

Hmm,

It's all working now, I changed the for loop into:

for (int i = 0; i < result.count; i++) {

Need to figure out how to grab 50 of them (random)...

[RLScott]

Originally Posted by rickrets

--EDIT--

You are right, I had to change every result.count to some int...

Is there no way to get it filled with something changeable??

The number 100 in [100] does not fill the array with anything. It just allocates a certain amount of memory. It does not hurt to allocate more than you need, unless that amount is so big that you start running out of memory. One instance of an int array of [100] elements is not going to hurt. Even [1000] would be fine. If you really need to allocate an array of variable size, then you should look at the C library functions available in malloc.h. But I would avoid that as much as possible because it brings its own special problems if you are not very careful.