Generating random numbers in Objective-C

You should use the arc4random_uniform() function. It uses a superior algorithm to rand. You don't even need to set a seed.

#include <stdlib.h>// ...// ...int r = arc4random_uniform(74);

The arc4random man page:

NAME     arc4random, arc4random_stir, arc4random_addrandom -- arc4 random number generatorLIBRARY     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))

Use the arc4random_uniform(upper_bound) function to generate a random number within a range. The following will generate a number between 0 and 73 inclusive.

arc4random_uniform(74)

arc4random_uniform(upper_bound) avoids modulo bias as described in the man page:

arc4random_uniform() will return a uniformly distributed random number less than upper_bound. arc4random_uniform() is recommended over constructions like ``arc4random() % upper_bound'' as it avoids "modulo bias" when the upper bound is not a power of two.

Same as C, you would do

#include <time.h>#include <stdlib.h>...srand(time(NULL));int r = rand() % 74;

(assuming you meant including 0 but excluding 74, which is what your Java example does)

Edit: Feel free to substitute random() or arc4random() for rand() (which is, as others have pointed out, quite sucky).