Test object subscripting in Objective-C

main.m

//
//  main.m
//  SubscriptingSample
//
//  Created by Robert Dimitrov on 6/19/13.
//  Copyright (c) 2013 Robert Dimitrov. All rights reserved.
//

#import <UIKit/UIKit.h>

#import "Person.h"
#import "PersonHolder.h"

int main(int argc, char *argv[]) {
    @autoreleasepool {
        Person *john = [[Person alloc] init];
        [john setFullName:@"John Appleseed"];
        
        Person *max = [[Person alloc] init];
        [max setFullName:@"Mad Max"];
        
        PersonHolder *personHoder = [[PersonHolder alloc] init];
        personHoder[0] = john;
        
        personHoder[@"Max"] = max;
        
        NSLog(@"%@", [personHoder[0] fullName]);
        NSLog(@"%@", [personHoder[@"Max"] fullName]);
    }
}

Person.h

//
//  Person.h
//  SubscriptingSample
//
//  Created by Robert Dimitrov on 6/19/13.
//  Copyright (c) 2013 Robert Dimitrov. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface Person : NSObject

@property (copy) NSString *fullName;

@end

Person.m

//
//  Person.m
//  SubscriptingSample
//
//  Created by Robert Dimitrov on 6/19/13.
//  Copyright (c) 2013 Robert Dimitrov. All rights reserved.
//

#import "Person.h"

@implementation Person

@end

PersonHolder.h

//
//  PersonHolder.h
//  SubscriptingSample
//
//  Created by Robert Dimitrov on 6/19/13.
//  Copyright (c) 2013 Robert Dimitrov. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface PersonHolder : NSObject

- (id)objectAtIndexedSubscript:(NSUInteger)idx;
- (void)setObject:(id)obj atIndexedSubscript:(NSUInteger)idx;

- (id)objectForKeyedSubscript:(id <NSCopying>)key;
- (void)setObject:(id)obj forKeyedSubscript:(id <NSCopying>)key;

@end

PersonHolder.m

//
//  PersonHolder.m
//  SubscriptingSample
//
//  Created by Robert Dimitrov on 6/19/13.
//  Copyright (c) 2013 Robert Dimitrov. All rights reserved.
//

#import "PersonHolder.h"

@interface PersonHolder ()

@property (copy) NSMutableArray *peopleArray;
@property (copy) NSMutableDictionary *peopleDictionary;

@end

@implementation PersonHolder

- (id)init {
    self = [super init];
    if (self) {
        _peopleArray = [[NSMutableArray alloc] init];
        _peopleDictionary = [[NSMutableDictionary alloc] init];
    }
    return self;
}

#pragma mark - Subscripting

- (id)objectAtIndexedSubscript:(NSUInteger)idx {
    return [self peopleArray][idx];
}

- (void)setObject:(id)obj atIndexedSubscript:(NSUInteger)idx {
    [self peopleArray][idx] = obj;
}

- (id)objectForKeyedSubscript:(id <NSCopying>)key {
    return [self peopleDictionary][key];
}

- (void)setObject:(id)obj forKeyedSubscript:(id <NSCopying>)key {
    [self peopleDictionary][key] = obj;
}

@end