Question

I want to store the array of NSDictionary to a file. So I write a function to convert from NSArray to NSString. But I got a very strange problem. Here is my code.

+ (NSArray *)arrayForString:(NSString*)dataString
{
    NSArray* stringArray = [dataString componentsSeparatedByString:ROW_SEPARATOR];
    NSLog(@"%@", stringArray);
    NSMutableArray* dictionaryArray = [[NSMutableArray alloc] initWithCapacity:0];
    for (int i = 0; i < [stringArray count]; i++)
    {
        NSString* string = [stringArray objectAtIndex:i];
        NSLog(@"%@", string);
        NSArray* subStrings = [string componentsSeparatedByString:COLUMN_SEPARATOR];
        NSDictionary* dic = [[NSDictionary alloc] initWithObjectsAndKeys:[subStrings objectAtIndex:0], PHOTO_NAME, [NSNumber numberWithUnsignedInt:[[subStrings objectAtIndex:1] unsignedIntValue]], PHOTO_SEQ_NO, nil];
        [dictionaryArray addObject:dic];
    }
    return dictionaryArray;
}

Here is the log:

2012-05-05 23:57:35.113 SoundRecognizer[147:707] (
    "new Photo/0",
    "new Photo/1"
)
2012-05-05 23:57:35.118 SoundRecognizer[147:707] new Photo/0
2012-05-05 23:57:35.123 SoundRecognizer[147:707] -[__NSCFString unsignedIntValue]: unrecognized selector sent to instance 0x1d18c0

How do I get a @”-” from this following array?!

2012-05-05 23:57:35.113 SoundRecognizer[147:707] (
    "new Photo/0",
    "new Photo/1"
)

Answer 1

NSString doesn’t have an unsignedIntValue method. Use intValue instead. But I’m not sure of the point of all this – you can write an array of dictionaries straight to a file anyway (as long as they only contain property list types) using writeToFile: atomically:.