Requiring many random numbers

Question

I'm trying to create a mastermind style game to build up my iOS objective c skills. I'm trying to create 6 random numbers between 0 and 9 using the following. I get different numbers when run at different times but all 6 numbers are always the same on each run.

NSNumber *n1 = [[NSNumber alloc]initWithInt:(random() % 10)];
NSNumber *n2 = [[NSNumber alloc]initWithInt:(random() % 10)];
NSNumber *n3 = [[NSNumber alloc]initWithInt:(random() % 10)];
NSNumber *n4 = [[NSNumber alloc]initWithInt:(random() % 10)];
NSNumber *n5 = [[NSNumber alloc]initWithInt:(random() % 10)];
NSNumber *n6 = [[NSNumber alloc]initWithInt:(random() % 10)];

Any help would be very useful.

Answer 1

Most likely you forgot to seed the random generator(i.e. add the following line before generating random numbers):

srandom(time(NULL));

Anyway, on iPhone you should use arc4random() function - it provides much better results and does not require seeding:

NSNumber *n1 = [[NSNumber alloc]initWithInt:(arc4random() % 10)];