Cocoa random string generator

gistfile1.m

// Rex Fatahi Jan 2014
// use as category for NSString*

+ (NSString *)randomNameGenerator:(NSInteger)characterLength
{
    NSString *letters = @"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
    NSMutableString *randomString = [NSMutableString stringWithCapacity:characterLength];
    
    for (int i = 0; i < characterLength; i++) {
        [randomString appendFormat: @"%C", [letters characterAtIndex: arc4random() % [letters length]]];
    }
    
    return randomString;
}