Compare two NSArrays and return number of differences

Question

How can I take two NSArrays, compare them, then return the number of differences, preferably the number of different objects, for example:

Array 1: one two

Answer 1

I found that the answer above didn't take arrays of differing size into account. If you do it as above, you should check to see which array.count is smaller and

[largerArray removeObjectsInArray:shorterArray];

OR

I made them both NSSets and then compared.

[set1 isEqualToSet:set2];

That way size and order are both dealt with properly! (I didn't need to know the number of differences)