Sort Object inside NSArray?

Question

I have an object, as below

#import <Foundation/Foundation.h>

@interface CountriesDAO : NSObject

@property (nonatomic, retain) NSString * countryname;

@end



#import "CountriesDAO.h"

@implementation CountriesDAO
@synthesize countryname;

@end

I have saved this in Array within appDelegate.

@property (nonatomic, retain) NSArray *countriesArray;

@synthesize countriesArray;

In another controller, I fetch it like

  NSArray *countriesArray = appDelegate.countriesArray; It works fine and I get array.

As I try to sort it by this way.

 NSArray *countriesArray1 = appDelegate.countriesArray;
    NSSortDescriptor *valueDescriptor = [[NSSortDescriptor alloc] initWithKey:@"countryname" ascending:YES];
    NSArray * descriptors = [NSArray arrayWithObject:valueDescriptor];

    countriesArray = [countriesArray1 sortedArrayUsingDescriptors:descriptors];

I get error

[__NSCFType count]: unrecognized selector sent to instance 0xa83b4d0
2013-11-01 13:21:08.882 ECP[13597:c07] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFType count]: unrecognized selector sent to instance 0xa83b4d0'

Here countriesArray is defined as

 @property (nonatomic, retain) NSArray *countriesArray;

How its not an Array, @property (nonatomic, retain) NSArray *countriesArray; — Duaan
– Duaan, Commented Nov 1, 2013 at 8:32
Can you show the code where you initialize the CountriesDAO-objects and put them in the array? This looks correct to me. — Accatyyc
– Accatyyc, Commented Nov 1, 2013 at 8:40
What you are storing into the array countryname or object of class CountriesDAO? — Apurv
– Apurv, Commented Nov 1, 2013 at 8:52
What makes you think that declaring countriesArray as an NSArray* makes it an NSArray? An object is whatever it is. Just because you assign it to an NSArray* doesn't make it one. And quite obviously, it isn't an NSArray. That's why you get an exception. Look at the code in the delegate. — gnasher729
– gnasher729, Commented Apr 10, 2014 at 11:48

Duaan · Accepted Answer · 2013-11-01 09:00:26Z

1

I did it like this and it worked for me.

countriesArray = [[NSMutableArray alloc] init];


for (CountriesDAO *info in appDelegate.countriesArray) {
    [countriesArray addObject:info.countryname];
}    

[countriesArray sortUsingSelector:@selector(localizedCaseInsensitiveCompare:)];

answered Nov 1, 2013 at 9:00

Duaan

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Comments

Alex Cio · Accepted Answer · 2015-01-27 13:08:07Z

1

You can also try...

[countriesArray1 sortUsingSelector:@selector(compare:)];

edited Jan 27, 2015 at 13:08

Alex Cio

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answered Nov 1, 2013 at 8:37

Konstantin

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3 Comments

Duaan Over a year ago

[Countries compare:]: unrecognized selector sent to instance 0x8c63cd0'

Accatyyc Over a year ago

That won't work. His code is correct, it's probably something that went wrong when he puts the objects in the original array

Konstantin Over a year ago

NSArray *countriesArray = [[NSArray alloc] init]; NSArray *countriesArray1 = [[NSArray alloc] initWithObjects:@"3",@"2",@"4",@"5",@"1", nil]; countriesArray = [countriesArray1 sortedArrayUsingSelector:@selector(compare:)]; NSLog(@"%@",countriesArray);

AntonPalich · Accepted Answer · 2013-11-01 08:53:26Z

0

Should work

NSMutableArray *sortedArray = [appDelegate.countriesArray mutableCopy];
[sortedArray sortUsingComparator:^NSComparisonResult(CountriesDAO *object1, 
                                                     CountriesDAO *object2) {                
    return [object1.countryname caseInsensitiveCompare:object2.countryname];
}];
NSArray *sortedCountriesArray = [sortedArray copy];

If something went wrong, check the type of object1 and object2

edited Nov 1, 2013 at 8:53

answered Nov 1, 2013 at 8:47

AntonPalich

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Comments

NANNAV · Accepted Answer · 2013-11-01 08:55:33Z

0

Its is simple Way to sort array in iOS,it's helps to you

[countriesArray sortUsingComparator:^NSComparisonResult(id obj1, id obj2) {
        return [ String_1 compare: String_2];
    }];

// String_1, String_2 are NSString,it's contains in countriesArray
// use  NSMutableArray to rearrange and change values in countriesArray

answered Nov 1, 2013 at 8:55

NANNAV

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Comments

Nikos M. · Accepted Answer · 2013-11-01 08:33:41Z

-1

If the array you want to sort contains NSString (which is what I get from your description) you can replace your sorting code with this:

sortedArray = [countriesArray1 sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];

answered Nov 1, 2013 at 8:33

Nikos M.

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5 Comments

Duaan Over a year ago

Countries localizedCaseInsensitiveCompare:]: unrecognized selector sent to instance CRASH ........

Nikos M. Over a year ago

Change NSArray *countriesArray1 = appDelegate.countriesArray; with NSMutableArray *countriesArray1 = [countriesArray1 addObjectsFromArray:appDelegate.countriesArray;

Accatyyc Over a year ago

The array contains CountriesDAO objects which have a countryname property

Duaan Over a year ago

This can't be a way to init NSMutableArray, two time countriesArray1 and what do you want to do by it?

Duaan Over a year ago

@Accatyyc, Yes, Array contains object, one more thing also comes in between, thats database,

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