Working with NSData as string

NSMutableData+Strings.h

//
//  NSMutableData+Strings.h
//
//  Created by Konstantin Simakov
//

#import <Foundation/Foundation.h>

@interface NSMutableData (Strings)

-(void)appendString:(NSString *)string;
-(void)appendFormat:(NSString *)format, ... NS_FORMAT_FUNCTION(1,2);

@end

NSMutableData+Strings.m

//
//  NSMutableData+Strings.m
//
//  Created by Konstantin Simakov
//

#import "NSMutableData+Strings.h"

@implementation NSMutableData (Strings)

-(void)appendString:(NSString *)string
{
    [self appendData:[string dataUsingEncoding:NSUTF8StringEncoding]];
}

-(void)appendFormat:(NSString *)format, ... NS_FORMAT_FUNCTION(1,2)
{
    va_list al;
    va_start(al, format);
    NSString *string = [[NSString alloc] initWithFormat:format arguments:al];
    [self appendData:[string dataUsingEncoding:NSUTF8StringEncoding]];
}

@end