how to convert NSString to NSArray

Question

I have a string like

NSString* str = @"[90, 5, 6]";

I need to convert it to an array like

NSArray * numbers = [90, 5 , 6];

I did a quite long way like this:

+ (NSArray*) stringToArray:(NSString*)str
{
    NSString *sep = @"[,";
    NSCharacterSet *set = [NSCharacterSet characterSetWithCharactersInString:sep];
    NSArray *temp=[str componentsSeparatedByCharactersInSet:set];

    NSMutableArray* numbers = [[NSMutableArray alloc] init];
    for (NSString* s in temp) {
        NSNumber *n = [NSNumber numberWithInteger:[s integerValue]];
        [numbers addObject:n];
    }

    return numbers;
}

Is there any neat and quick way to do such conversion?

Thanks

Answer 1

First remove the unwanted characters from the string, like white spaces and braces:

NSString* str = @"[90, 5, 6]";
NSCharacterSet* characterSet = [[NSCharacterSet
                                 characterSetWithCharactersInString:@"0123456789,"] invertedSet];
NSString* newString = [[str componentsSeparatedByCharactersInSet:characterSet]
                       componentsJoinedByString:@""];

You will have a string like this: 90,5,6. Then simply split using the comma and convert to NSNumber:

NSArray* arrayOfStrings = [newString componentsSeparatedByString:@","];
NSMutableArray* arrayOfNumbers = [NSMutableArray arrayWithCapacity:arrayOfStrings.count];
for (NSString* string in arrayOfStrings) {
    [arrayOfNumbers addObject:[NSDecimalNumber decimalNumberWithString:string]];
}

Using the NSString category from this response it can be simplified to:

NSArray* arrayOfStrings = [newString componentsSeparatedByString:@","];
NSArray* arrayOfNumbers = [arrayOfStrings valueForKey: @"decimalNumberValue"];