Question

how do i check an array if objectatIndex has any values? im using a forloop

for (i = 0; i < 6 ; i++)
{
    if ([array objectAtIndex: i] == NULL)//This doesnt work.
    {
        NSLog(@"array objectAtIndex has no data");
    }
}

Answer 1

You can’t store nil in a Foundation collection class such as NSArray, you have to use NSNull. To check to see if a member of the array is NSNull, you would do this:

for (int i = 0; i < 6; i ++) {
    if ([array objectAtIndex:i] == [NSNull null]) {
        NSLog(@"object at index %i has no data", i);
    }
}

If you want to see how many items are in the array, use -[NSArray count]. If you want to iterate through the array to see if any object is NSNull, but you don’t care which one, you could use fast enumeration or -[NSArray containsObject:]:

for (id anObject in array) {
    if (anObject == [NSNull null]) {
        // Do something
    }
}

or

if ([array containsObject:[NSNull null]]) {
    // Do something
}