The comparator is given as a selector argument. Here we used default case-insensitive compare function. NSArray:sortedArrayUsingSelector is frequently used in list arrangement and so on, so it's worth to remember this example.
NSArray *sortedArray = [myArray2 sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)]; // This will return a sorted array that looks like [@"bar",@"baz",@"foo"]