Question

I have an application which retrieves a lot of numerical data from a server and saves it into a NSMUtableArray. Now the values are floats which look like 10.0; 11.2; 30.003; 109.23, etc.

Now I used the sortUsingSelector(@selector(compare:)) method to sort my array to find the largest and the smallest value. My output is following:

10.0
109.23
11.2
30.003

Now I suppose the compare: selector treats the values as strings and orders them accordingly. But thats not what I want. I want the values to be ordered according to their float value.
So my question is: Is there any way to sort the floats array according to their numerical value?

Answer 1

There may be a short cut for the comparison, and there’s no error checking, but something like this should do the trick:

NSArray* sorted = [unsorted sortedArrayWithOptions:0 usingComparator:^(id v1, id v2) {
  float f1 = [v1 floatValue];
  float f2 = [v2 floatValue];

  if (f1 == f2) return NSOrderedSame;
  return (f1 < f2) ? NSOrderedAscending : NSOrderedDescending;
}];

Or you could just store the values as NSNumber as they come in.