Sorting NSArray

[bergetun]

Im having a hard time understanding how sorting of arrays are working in ObjC.

I have a simple class (Person) that have a couple of properties such as name, phoneNumber, address etc.

Then I have a array of Person's in a NSArray.

How can I easily sort the array based on names in the Person class ?

This is how I would do it in C#

Array.Sort(_myPersonArray, delegate(Result x, Result y)
{
return x.Name.CompareTo(y.Name);
});

[iDevGuy]

Reference to the sorted... instance methods of NSArray should help.

[myersn024]

I use NSSortDescriptors to sort my arrays, but there are other ways. The following code is an example.

NSSortDescriptor *lastNameDescriptor = [[NSSortDescriptor alloc] initWithKey:@"lastName" ascending:YES];
[peopleArray sortUsingDescriptors:[NSArray arrayWithObject:lastNameSorter]];

In the in the NSSortDescriptor alloc-init line, you'll have to change the initWithKey parameter from lastName to whatever the name of your last name variable is. You'll also have to have a property declared for your last name variable before you can use is as a key.

[PhoneyDeveloper]

Here's how I do it in my Person class:

This line does the sort in the NSMutableArray containing Person objects:

		[array sortUsingSelector:@selector(compareFullCommaName:)];

This method is implemented in the Person class:

-(NSComparisonResult)compareFullCommaName:(MPerson*)inPerson
{
	NSString*	selfCommaName = [self textForField:kPersonFullNameComma];
	NSString*	otherPersonCommaName = [inPerson textForField:kPersonFullNameComma];
	
	return [selfCommaName compare:otherPersonCommaName];
}

The full comma names are 'lastname, firstname' but you get the idea. You need a comparison method that returns an appropriate NSComparisonResult. Look at the docs for sortUsingSelector:

BTW, answers to basic Cocoa/Foundation questions like this can be found on Cocoabuilder.com. See for instance http://www.cocoabuilder.com/search/a...rds=sort+array

[bergetun]

Thanks for the help guys, it really helped

Jimmy