How to sort array controller alphabetically with numbers last in objective-c?

问题

I have an NSArrayController and I would like to sort the contents so that anything with English alphabets are sorted first and then anything with numbers and non English characters are sorted last.

For example: A, B , C ... Z, 1 , 2, 3 ... 9, 구, 결, ...

Currently I only know how to sort items in alphabetical order. Suggestions?

NSSortDescriptor *sort = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];
        [dataController setSortDescriptors: [NSArray arrayWithObject: sort]];

回答1:

You can use sortedArrayUsingComparator to customize the sort algorithm to your needs. For instance, you can give precedence to symbols with this lines:

NSArray *assorted = [@"1 2 3 9 ; : 구 , 결 A B C Z ! á" componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
NSArray *sorted = [assorted sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    /* NSOrderedAscending, NSOrderedSame, NSOrderedDescending */
    BOOL isPunct1 = [[NSCharacterSet punctuationCharacterSet] characterIsMember:[(NSString*)obj1 characterAtIndex:0]];
    BOOL isPunct2 = [[NSCharacterSet punctuationCharacterSet] characterIsMember:[(NSString*)obj2 characterAtIndex:0]];
    if (isPunct1 && !isPunct2) {
        return NSOrderedAscending;
    } else if (!isPunct1 && isPunct2) {
        return NSOrderedDescending;
    }
    return [(NSString*)obj1 compare:obj2 options:NSDiacriticInsensitiveSearch|NSCaseInsensitiveSearch];         
}];

To put English characters before non-English ones, it'd be enough to use NSDiacriticInsensitiveSearch | NSCaseInsensitiveSearch as options, no fancy algorithm required.

If you need to support iOS without blocks try sortedArrayUsingSelector.

回答2:

Another solution by testing, if a string is latin1-encodeable:

test for both strings, if the first character is a latin (aka english) character
if both are, test if both starts either with a letter or a number. In both cases, leave it up the compare:
else, if one starts with the number and one with a letter, return NSOrderingAscending, if the one with letter its first, otherwise NSOrderingDescending
If both strings aren't latin, let compare: decide again
if one is latin, and one not, return NSOrderingAscending if the latin is first, otherwise NSOrderingDescending

the code

NSArray *array = [NSArray arrayWithObjects:@"peach",@"apple",@"7",@"banana",@"ananas",@"5", @"papaya",@"4",@"구",@"결",@"1" ,nil];

array = [array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    NSString *s1 = [obj1 substringToIndex:1];
    NSString *s2 = [obj2 substringToIndex:1];
    BOOL b1 = [s1 canBeConvertedToEncoding:NSISOLatin1StringEncoding];
    BOOL b2 = [s2 canBeConvertedToEncoding:NSISOLatin1StringEncoding];

    if ((b1 == b2) && b1) {//both number or latin char
        NSRange r1 = [s1 rangeOfCharacterFromSet:[NSCharacterSet decimalDigitCharacterSet]];
        NSRange r2 = [s2 rangeOfCharacterFromSet:[NSCharacterSet decimalDigitCharacterSet]];
        if (r1.location == r2.location ) { // either both start with a number or both with a letter
            return [obj1 compare:obj2 options:NSDiacriticInsensitiveSearch|NSCaseInsensitiveSearch]; 
        } else {  // one starts wit a letter, the other with a number
            if ([s1 rangeOfCharacterFromSet:[NSCharacterSet decimalDigitCharacterSet]].location == NSNotFound) {
                return NSOrderedAscending;
            }
            return NSOrderedDescending;
        }
    } else if((b1 == b2) && !b1){ // neither latin char
        return [obj1 compare:obj2 options:NSDiacriticInsensitiveSearch|NSCaseInsensitiveSearch];
    } else { //one is latin char, other not
        if (b1) return NSOrderedAscending;
        return NSOrderedDescending;
    }

}];
for (NSString *s in array) NSLog(@"%@", s);

result

ananas
apple
banana
papaya
peach
1
4
5
7
구
결

回答3:

I don't think you can do that kind of sorting without defining your own comparison function.

To this aim, you could use sortedArrayUsingFunction:

[array sortedArrayUsingFunction:f context:userContext];

where f is defined as:

NSInteger f(id num1, id num2, void *context)
{
   int v1 = [num1 intValue];
   int v2 = [num2 intValue];
   if (...)
     return NSOrderedAscending;
   else if (...)
     return NSOrderedDescending;
   else
     return NSOrderedSame;
}

If you prefer not creating function for doing this you could use the block-version of the method, sortedArrayUsingComparator:

[array sortedArrayUsingComparator: ^(id obj1, id obj2) {
                                             return NSOrderedSame;
                                   }];

回答4:

A sort descriptor based on a comparator should do the trick (note: not tested).

NSComparator cmp = ^(id str1, id str2) {

// Make your sorting
    if ( /* str1 before str2 */ )
    return NSOrderedAscending
    else if ( /* str2 after str1 */ )
    return NSOrderedDescending
    else 
    return NSOrderedSame
};

NSSortDescriptor *sd = [NSSortDescriptor sortDescriptorWithKey: sortKey ascending: YES comparator: cmp];

NSArrayController *ac = // ...

[ac setSortDescriptor: sd];

You of course have to define your own sort order algorithm - but this example should show how to use a sort descriptor for an array controller.

回答5:

One thing is missing to answer properly to the question : NSNumericSearch

NSArray *assorted = [@"1 2 3 9 ; : 구 , 결 A B C Z ! á" componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
NSArray *sorted = [assorted sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    /* NSOrderedAscending, NSOrderedSame, NSOrderedDescending */
    BOOL isPunct1 = [[NSCharacterSet punctuationCharacterSet] characterIsMember:[(NSString*)obj1 characterAtIndex:0]];
    BOOL isPunct2 = [[NSCharacterSet punctuationCharacterSet] characterIsMember:[(NSString*)obj2 characterAtIndex:0]];
    if (isPunct1 && !isPunct2) {
        return NSOrderedAscending;
    } else if (!isPunct1 && isPunct2) {
        return NSOrderedDescending;
    }
    return [(NSString*)obj1 compare:obj2 options:NSDiacriticInsensitiveSearch|NSCaseInsensitiveSearch|NSNumericSearch]|;         
}];

来源：https://stackoverflow.com/questions/8242735/how-to-sort-array-controller-alphabetically-with-numbers-last-in-objective-c

标签

objective-c

cocoa

sorting

nssortdescriptor