Converting NSString to NSData and vice versa

Question

I am having an issue while trying to convert NSString to NSData and vice versa. I am trying to store encrypted string to my database. For that I am

Answer 1

NSString to NSData:

NSString* str= @"teststring";
NSData* data=[str dataUsingEncoding:NSUTF8StringEncoding];

NSData to NSString:

NSString* newStr = [[NSString alloc] initWithData:theData
                                         encoding:NSUTF8StringEncoding];