Translate Vanity Phone Numbers to only numbers

gistfile1.m

#import "NSString+Utils.h"

@implementation NSString (Utils)

- (NSString *)translateVanityPhoneNumber
{
    NSMutableString *resultString = [NSMutableString stringWithCapacity:self.length];  
    NSScanner *scanner = [NSScanner scannerWithString:[self uppercaseString]];  
    NSCharacterSet *set = [NSCharacterSet letterCharacterSet];
    while ([scanner isAtEnd] == NO) {  
        NSString *buffer;  
        if ([scanner scanUpToCharactersFromSet:set intoString:&buffer]) {  
            [resultString appendString:buffer];       
        } else {
            if([scanner scanCharactersFromSet:set intoString:&buffer]) {
                for (NSUInteger n=0; n<buffer.length; n++) {
                    switch ([buffer characterAtIndex:n]) {
                        case 'A':
                        case 'B':
                        case 'C':
                            [resultString appendString:@"2"];
                            break;
                        case 'D':
                        case 'E':
                        case 'F':
                            [resultString appendString:@"3"];
                            break;
                        case 'G':
                        case 'H':
                        case 'I':
                            [resultString appendString:@"4"];
                            break;
                        case 'J':
                        case 'K':
                        case ':':
                            [resultString appendString:@"5"];
                            break;
                        case 'M':
                        case 'N':
                        case 'O':
                            [resultString appendString:@"6"];
                            break;
                        case 'P':
                        case 'Q':
                        case 'R':
                        case 'S':
                            [resultString appendString:@"7"];
                            break;
                        case 'T':
                        case 'U':
                        case 'V':
                            [resultString appendString:@"8"];
                            break;
                        case 'W':
                        case 'X':
                        case 'Y':
                        case 'Z':
                            [resultString appendString:@"9"];
                            break;
                    }
                }
            }
        }  
    } 
    return resultString;
}

@end