Generating random numbers in Objective-C

Question

I\'m a Java head mainly, and I want a way to generate a pseudo-random number between 0 and 74. In Java I would use the method:

Random.nextInt(74)
         


        

Answer 1

According to the manual page for rand(3), the rand family of functions have been obsoleted by random(3). This is due to the fact that the lower 12 bits of rand() go through a cyclic pattern. To get a random number, just seed the generator by calling srandom() with an unsigned seed, and then call random(). So, the equivalent of the code above would be

#import 
#import 

srandom(time(NULL));
random() % 74;

You'll only need to call srandom() once in your program unless you want to change your seed. Although you said you didn't want a discussion of truly random values, rand() is a pretty bad random number generator, and random() still suffers from modulo bias, as it will generate a number between 0 and RAND_MAX. So, e.g. if RAND_MAX is 3, and you want a random number between 0 and 2, you're twice as likely to get a 0 than a 1 or a 2.