Use of random numbers in objective-C (arc4random (), random (), and ccrandom_0_1 ())

1. Use of random numbers

1) arc4random () is more accurate and does not need to be generated immediately.

Usage:

The code for getting an integer between 0 and X-1 through arc4random () is as follows:

Int value = arc4random () % x;

The code for getting an integer between 1 and X is as follows:

Int value = (arc4random () % x) + 1;

 

2). It is used in ccrandom_0_1 () cocos2d and the range is [0, 1].

Usage:

Float random = ccrandom_0_1 () * 5; // [] ccrandom_0_1 () value range: []

 

3) set the seed when random () needs Initialization

Usage:

Srandom (unsigned INT) Time (time_t *) null); // set the seed during initialization.

From: http://www.cnblogs.com/xuling/archive/2012/02/28/2370692.html