# FAQ overflow

#### 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)



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

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