Sort NSArray using sortedArrayUsingComparator, number last.

SortNSArrayNumberLast.m

- (NSArray *)sortArrayNumberLast:(NSArray *)arr {
    
    return [arr sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
        NSString *s1 = [obj1 substringToIndex:1];
        NSString *s2 = [obj2 substringToIndex:1];
        
        if ([s1 rangeOfCharacterFromSet:[NSCharacterSet decimalDigitCharacterSet]].location == [s2 rangeOfCharacterFromSet:[NSCharacterSet decimalDigitCharacterSet]].location) {
            return  [obj1 compare:obj2];
        } else {
            if ([s1 rangeOfCharacterFromSet:[NSCharacterSet decimalDigitCharacterSet]].location == NSNotFound) {
                return NSOrderedAscending;
            }
        }
        return  NSOrderedDescending;
    }];
}