问题
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 three
Array 2: two four one
I would like that to return "1"
回答1:
You can do this by using an intermediate NSMutableArray:
NSArray *array1 = [NSArray arrayWithObjects:@"One", @"Two", @"Three", nil];
NSArray *array2 = [NSArray arrayWithObjects:@"Two", @"Four", @"One", nil];
NSMutableArray *intermediate = [NSMutableArray arrayWithArray:array1];
[intermediate removeObjectsInArray:array2];
NSUInteger difference = [intermediate count];
With that way, only common elements will be removed.
回答2:
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)
来源：https://stackoverflow.com/questions/2939348/compare-two-nsarrays-and-return-number-of-differences