Sort a mutable array based on the sort of another mutable array?

Question

Is there a way that I can sort an array based on an alphabetical sort that I did to another array? The practical use to this would be trying to associate an array with usernames to an array that contains those usernames' names. I have two separate lists containing this information and I need to alphabetically sort the users based on their name, but I need to access their username too. So in order to do this I'm trying to have both pieces of data within the table view cell and just show the name and hide the username.

I can't reverse sort the array containing the names to the usernames because if two people had the same names this would cause many problems.

I tried using a NSMutableDictionary but this didn't work. Any help would be extremely helpful!

Rob Napier · Accepted Answer · 2015-08-13 19:46:52Z

2

I have two separate lists containing this information

There's your problem. Don't use two data structures to store parts of one object.

Create a model object that represents a user and includes both the identifier and the name. Then everything is easy. The entire object is tiny:

@interface User
@property (nonatomic, readwrite, copy) NSString *identifier;
@property (nonatomic, readwrite, copy) NSString *name;
@end
@implementation
@end

Sorting objects by properties is simple.

Even if other parts of the system didn't use this object, I'd still create it as a "view model" object just for this view controller. (But it's probably better to treat it as a regular model object and use it throughout your system.)

answered Aug 13, 2015 at 19:46

Rob Napier

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3 Comments

Lehman2020 Over a year ago

This does makes much more sense then working with two arrays. When you say create a model object, can you provide more information on how to do that?

Rob Napier Over a year ago

The above implementation is a model object. It just means "an object that holds data." A "view model" object is just one that holds data specifically to make things easy on views that display them. Sometimes they're organized a little differently (might hold attributed strings or screen coordinates), but it's just a specialized version of a model object. The MVC pattern is one of the core pieces of Cocoa development. developer.apple.com/library/ios/documentation/General/…

Rob Napier Over a year ago

The key point is that you have a model which holds all the data, views which display the data, and controllers that coordinate between the two. View Controllers should never hold data. They just hook up views that need the data to models that hold it. (A fancier version called MVVM has started to become popular, but it's just a further extension on this idea, adding view models as an explicit rather than "we just often do that" layer.)

chaitanya.varanasi · Accepted Answer · 2015-08-13 19:35:56Z

0

I'm not sure what you are really asking here.

But let me have a crack at this. Assuming you have an alphabetically sorted array of usernames. From that, why dont you create a NSHastable with <key,value>=<username,name>.

You also wont have the problem where two names will conflict with each other, assuming your usernames are unique.

answered Aug 13, 2015 at 19:35

chaitanya.varanasi

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