when to use the various sort methods of NSArray?

The doco explains what the NSArray sort methods are, but is anyone able to give a bullet point say on when/why you'd use a particular method? i.e. under what circumstances in you code would you use method XXX over method YYY. For:

• sortedArrayUsingComparator
• sortedArrayUsingDescriptors
• sortedArrayUsingFunction:context
• sortedArrayUsing开发者_StackOverflowSelector

See Collection Programming Topics: Sorting Arrays for more general information. If you're looking at the class reference documentation, be sure to check out the "Companion guides" that are listed for more practical, real-world advice on how the classes work.

Basically, sortedArrayUsingSelector: and sortedArrayUsingFunction:context: have been around since 10.0/iOS 2.0. They're not as flexible as the other methods which came later.

If you have an array of relatively simple objects, like NSNumbers or NSStrings, you could use [numbers sortedArrayUsingSelector:@selector(compare:)] to easily sort the objects.

If, on the other hand, you have a more complex model object that has multiple properties, such as age, name, date, NSSortDescriptors work well. Those were added in OS X 10.3/iOS 2.0. The allow you to do something like first sort by age, then by name, and then by date.