Listing the content of an array in alphabetical order

Question

I have an array, with some names (String) in it.

1.) I want to list these names in the array in alphabetical order. 2.) Later i will add some more names to this array, so it had to get appended to this array.

How can i do this programatically ?

note: i don't have any code to demonstrate my working so far. i just have an array created.

EDIT

If my array declaration is ;

NSArray *array = [NSArray arrayWithObjects:@"A",@"C",@"B", @"M",nil];

how can i sort this ?

Answer 1

This will do what you need:

NSArray * sortedArray = [yourArray sortedArrayUsingSelector: @selector(caseInsensitiveCompare:)];

Of course, some people might ask why you didn't search the Apple docs for "sort array" before asking the question. Not me though. I'm happy to take the points!

Answer 2

You should really try getting used to looking at documentation - once you get the hang of it you can figure things out pretty quickly

The docs for NSArray give you the exact way to sort an array:

NSArray *array       = [NSArray arrayWithObjects:@"A", @"C", @"B", @"M", nil];
NSArray *sortedArray = [array sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];

---

Now considering you are wanting to add objects later you will most likely use an NSMutableArray the docs for NSMutableArray show the method:

- (void)sortUsingSelector:(SEL)comparator

Therefore you could use

NSMutableArray *myMutableArray = [NSMutableArray arrayWithObjects:@"c", @"a", @"b", nil];
[myMutableArray sortUsingSelector:@selector(caseInsensitiveCompare:)];

which will sort your array in place resulting in

2012-01-10 17:47:11.477 Untitled[11904:707] (
    a,
    b,
    c
)

Answer 3

This requires that you sort the Array (and you would need to do after new values get added to). This is pretty simple to do:

NSArray *sortedArray = [myArray sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];

This example would be case insensitive - but you could do case sensitive as well.

Answer 4

If you want to be able to append later, then you should use the mutable type of either NSArray or NSDictionary . If the array contains only names with no other data associated, then the easiest is to use an NSMutableArray to store them.

To alphabetize, you can use the NSArray method sortedArrayUsingSelector: together with @selector(caseInsensitiveCompare:) . This does all the work for you as efficiently as possible.