the implementation of Cesar crypt method

gistfile1.m

//
//  CVLogicManager.m
//  CesarShifr
//
//  Created by Kanybek Momukeev on 6/12/13.
//  Copyright (c) 2013 Kanybek Momukeev. All rights reserved.
//

#import "CVLogicManager.h"
@interface CVLogicManager()
@property (nonatomic, strong) NSMutableArray *alphabetArray;
@property (nonatomic) NSUInteger keyShift;
@end

@implementation CVLogicManager

- (NSMutableArray *)alphabetArray
{
    if (!_alphabetArray) {
        _alphabetArray = [NSMutableArray new];
    }
    return _alphabetArray;
}

- (void)setshift:(NSUInteger)shift
{
    self.keyShift = shift;
}

- (void)setAlphabetWithString:(NSString *)string
{
    [self.alphabetArray removeAllObjects];
    const char *charArray = [string UTF8String];
    size_t sizeOfCharArray = strlen(charArray);
    for (int index = 0; index < sizeOfCharArray; index ++)
    {
        NSNumber *charNumberValue = @(charArray[index]);
        [self.alphabetArray addObject:charNumberValue];
    }
}



- (NSString *)shifreString:(NSString *)originalString
{
    const char *originalCharArray = [originalString UTF8String];
    size_t sizeOfCharArray = strlen(originalCharArray);
    NSMutableString *shifreString = [NSMutableString string];
    
    
    for (int index = 0; index < sizeOfCharArray; index ++)
    {
        NSNumber *charNumberValue = @(originalCharArray[index]);
        if ([self.alphabetArray indexOfObject:charNumberValue] != NSNotFound)
        {
            NSUInteger indexOfChar = [self.alphabetArray indexOfObject:charNumberValue];
            NSUInteger shiftedIndex = (indexOfChar + self.keyShift) % self.alphabetArray.count;
            NSNumber *newShifreNumber = [self.alphabetArray objectAtIndex:shiftedIndex];
            [shifreString appendString:[NSString stringWithFormat:@"%c",[newShifreNumber charValue]]];
        }else
        {
            [shifreString appendString:[NSString stringWithFormat:@"%c",[charNumberValue charValue]]];
        }
    }
    
    return shifreString;
}




@end