I want to sort an array using NSSortDescriptor

Question

I am having a problem regarding sorting an array w.r.t database:

NSSortDescriptor *sorter = [[NSSortDescriptor alloc] initWithKey:@\"w\" ascending:YES];
NSAr         


        

Answer 1

An alternative form of Apple's finder sort with locale method uses the comparator block, helpful if you're in an ARC environment and don't want to deal with bridging casts, etc:

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"your_string_key" ascending:YES comparator:^NSComparisonResult(id obj1, id obj2) {
    NSStringCompareOptions comparisonOptions = NSCaseInsensitiveSearch | NSNumericSearch | NSWidthInsensitiveSearch | NSForcedOrderingSearch;
    NSRange string1Range = NSMakeRange(0, ((NSString *)obj1).length);
    return [(NSString *)obj1 compare: (NSString *)obj2 options: comparisonOptions range: string1Range locale: [NSLocale currentLocale]];
}];

NSArray *sortedArray = [originalArray sortedArrayUsingDescriptors:@[sortDescriptor]];

I too would recommend storing the current locale in a local variable for efficiency purposes.

Answer 2

This code is working fine for me.

- (void)sortSearchResultWithInDocumentTypeArray:(NSMutableArray *)aResultArray basedOn:(NSString *)aSearchString {

    NSSortDescriptor * frequencyDescriptor =[[NSSortDescriptor alloc] initWithKey:aSearchString ascending:YES comparator:^(id firstDocumentName, id secondDocumentName) {

        static NSStringCompareOptions comparisonOptions =
        NSCaseInsensitiveSearch | NSNumericSearch |
        NSWidthInsensitiveSearch | NSForcedOrderingSearch;

        return [firstDocumentName compare:secondDocumentName options:comparisonOptions];
     }];

    NSArray * descriptors =    [NSArray arrayWithObjects:frequencyDescriptor, nil];
    [aResultArray sortUsingDescriptors:descriptors];
}

Answer 3

May I suggest using -localizedStandardCompare: (NSString)?

"This method should be used whenever file names or other strings are presented in lists and tables where Finder-like sorting is appropriate. The exact sorting behavior of this method is different under different locales and may be changed in future releases."

Answer 4

I think this will do the trick for you. The docs for it are here: String Programming Guide

Add this little function written by Apple.

int finderSortWithLocale(id string1, id string2, void *locale)
{
    static NSStringCompareOptions comparisonOptions =
        NSCaseInsensitiveSearch | NSNumericSearch |
        NSWidthInsensitiveSearch | NSForcedOrderingSearch;

    NSRange string1Range = NSMakeRange(0, [string1 length]);

    return [string1 compare:string2
                    options:comparisonOptions
                    range:string1Range
                    locale:(NSLocale *)locale];
}

Make sure that you copy the function definition into your header, or you'll get a compile error on your sorted array.

For your sorted array, use this method:

[mGlossaryArray sortedArrayUsingFunction:finderSortWithLocale context:[NSLocale currentLocale]];

Your results will look like this:

• c
• cabin
• cafe
• Cancer
• Chinese
• Christianity
• Christmas
• Coke

Answer 5

You may use this for sorting an array according to name thats also contains small letter:

NSSortDescriptor *sorter = [NSSortDescriptor sortDescriptorWithKey:@"w" ascending:YES selector:@selector(caseInsensitiveCompare:)];

NSArray *sortDescriptors = [NSArray arrayWithObject:sorter]; 

[mGlossaryArray sortUsingDescriptors:sortDescriptors];

This code work fine for me to sort name according to alphabets that has also small character i.e. rocky,Ajay,john,Bob etc.

Answer 6

Take a look here: Creating and Using Sort Descriptors

You can compare as case-insensitive.

NSSortDescriptor *sorter = [[[NSSortDescriptor alloc]
          initWithKey:@"w"
          ascending:YES
          selector:@selector(localizedCaseInsensitiveCompare:)] autorelease];
NSArray *sortDescriptors = [NSArray arrayWithObject: sorter];
[mGlossaryArray sortUsingDescriptors:sortDescriptors];