Objective-C : Sorting NSMutableArray containing NSMutableArrays - objective-c

Question

I'm currently using NSMutableArrays in my developments to store some data taken from an HTTP Servlet.
Everything is fine since now I have to sort what is in my array.
This is what I do :
NSMutableArray *array = [[NSMutableArray arrayWithObjects:nil] retain];
[array addObject:[NSArray arrayWithObjects: "Label 1", 1, nil]];
[array addObject:[NSArray arrayWithObjects: "Label 2", 4, nil]];
[array addObject:[NSArray arrayWithObjects: "Label 3", 2, nil]];
[array addObject:[NSArray arrayWithObjects: "Label 4", 6, nil]];
[array addObject:[NSArray arrayWithObjects: "Label 5", 0, nil]];
First column contain a Label and 2nd one is a score I want the array to be sorted descending.
Is the way I am storing my data a good one ? Is there a better way to do this than using NSMutableArrays in NSMutableArray ?
I'm new to iPhone dev, I've seen some code about sorting but didn't feel good with that.
Thanks in advance for your answers !

Answer 1

This would be much easier if you were to create a custom object (or at least use an NSDictionary) to store the information, instead of using an array.
For example:
//ScoreRecord.h
#interface ScoreRecord : NSObject {
NSString * label;
NSUInteger score;
}
#property (nonatomic, retain) NSString * label;
#property (nonatomic) NSUInteger score;
#end
//ScoreRecord.m
#import "ScoreRecord.h"
#implementation ScoreRecord
#synthesize label, score;
- (void) dealloc {
[label release];
[super dealloc];
}
#end
//elsewhere:
NSMutableArray * scores = [[NSMutableArray alloc] init];
ScoreRecord * first = [[ScoreRecord alloc] init];
[first setLabel:#"Label 1"];
[first setScore:1];
[scores addObject:first];
[first release];
//...etc for the rest of your scores
Once you've populated your scores array, you can now do:
//the "key" is the *name* of the #property as a string. So you can also sort by #"label" if you'd like
NSSortDescriptor * sortByScore = [NSSortDescriptor sortDescriptorWithKey:#"score" ascending:YES];
[scores sortUsingDescriptors:[NSArray arrayWithObject:sortByScore]];
After this, your scores array will be sorted by the score ascending.

Answer 2

You don't need to create a custom class for something so trivial, it's a waste of code. You should use an array of NSDictionary's (dictionary in ObjC = hash in other languages).
Do it like this:
NSMutableArray * array = [NSMutableArray arrayWithObjects:
[NSDictionary dictionaryWithObject:#"1" forKey:#"my_label"],
[NSDictionary dictionaryWithObject:#"2" forKey:#"my_label"],
[NSDictionary dictionaryWithObject:#"3" forKey:#"my_label"],
[NSDictionary dictionaryWithObject:#"4" forKey:#"my_label"],
[NSDictionary dictionaryWithObject:#"5" forKey:#"my_label"],
nil];
NSSortDescriptor * sortDescriptor = [[[NSSortDescriptor alloc] initWithKey:#"my_label" ascending:YES] autorelease];
[array sortUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]];