Question

Is there a simple way to do fast enumeration on a range of objects in an array? Something like…

for (Object *object in myArray startingAtIndex:50) {
    //do stuff
}

…to avoid having to do something like this…

for (Object *object in myArray) {
    NSUInteger index = [myArray indexOfObject:object];
    if (index >= 50) {
        //do stuff
    }
}

Thanks.

Answer 1

These come to my mind:

for (Object *object in [myArray subArrayWithRange:NSMakeRange(50, ([myArray count] - 49))]) {
    //do stuff
}

Which creates a temporary array though, thus potentially being slower (benchmark it!) than manual enumeration like this:

NSUInteger arrayCount = [myArray count];
for (NSUInteger i = 50; i < arrayCount; i++) {
    Object *object = [myArray objectAtIndex];
    // do stuff
}