Split an NSString into an NSArray of its characters.

split_string.m

#import <Foundation/Foundation.h>

int main(int argc, char *argv[]) {
    @autoreleasepool {
        NSString* s = @"antidisestablishmentarianism";

        unichar* buffer = (unichar *)malloc(sizeof(unichar) * [s length]);
        [s getCharacters:buffer range:NSMakeRange(0, [s length])];

        NSMutableArray* temp = [NSMutableArray arrayWithCapacity:[s length]];

        for (int i = 0; i < [s length]; i++) {
            [temp addObject:[NSString stringWithFormat:@"%C", buffer[i]]];
        }

        free(buffer);

        NSArray* characters = [NSArray arrayWithArray:temp];

        NSLog(@"%@", characters);
    }

    return 0;
}

@interface NSString (MDXComponents)
- (NSArray *)mdx_components;
@end

@implementation NSString (MDXComponents)

- (NSArray *)mdx_components
{
    unichar* buffer = (unichar *)malloc(sizeof(unichar) * [self length]);
    [self getCharacters:buffer range:NSMakeRange(0, [self length])];
    
    NSMutableArray* temp = [NSMutableArray arrayWithCapacity:[self length]];
    
    for (int i = 0; i < [self length]; i++) {
        [temp addObject:[NSString stringWithFormat:@"%C", buffer[i]]];
    }
    
    free(buffer);
    
    return [NSArray arrayWithArray:temp];
}

@end

@interface NSString (MDXString)
- (NSArray *)allCharacters;
@end

@implementation NSString (MDXString)

- (NSArray *)allCharacters
{
    CFStringRef ref = (__bridge CFStringRef)self;
    NSMutableArray* characters = [NSMutableArray arrayWithCapacity:[self length]];
    
    for (int i = 0; i < [self length]; i++) {
        [characters addObject:[NSString stringWithFormat:@"%C", CFStringGetCharacterAtIndex(ref, i)]];
    }
    
    return [NSArray arrayWithArray:characters];
}

@end