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:
I'm not interested in a discussion about seeds or true randomness, just how you accomplish the same task in Objective-C. I've scoured The Google, and it just seems to be lots of different and conflicting bits of information.
You should use the arc4random() function. It uses a superior algorithm to rand. You don't even need to set a seed.
#include <stdlib.h> ... ... int r = arc4random() % 74;
The arc4random man page:
NAME arc4random, arc4random_stir, arc4random_addrandom -- arc4 random number generator LIBRARY Standard C Library (libc, -lc) SYNOPSIS #include <stdlib.h> u_int32_t arc4random(void); void arc4random_stir(void); void arc4random_addrandom(unsigned char *dat, int datlen); DESCRIPTION The arc4random() function uses the key stream generator employed by the arc4 cipher, which uses 8*8 8 bit S-Boxes. The S-Boxes can be in about (2**1700) states. The arc4random() function returns pseudo- random numbers in the range of 0 to (2**32)-1, and therefore has twice the range of rand(3) and random(3). The arc4random_stir() function reads data from /dev/urandom and uses it to permute the S-Boxes via arc4random_addrandom(). There is no need to call arc4random_stir() before using arc4random(), since arc4random() automatically initializes itself. EXAMPLES The following produces a drop-in replacement for the traditional rand() and random() functions using arc4random(): #define foo4random() (arc4random() % ((unsigned)RAND_MAX + 1))