A method of generating random numbers in objective-c _ios

This paper briefly introduces several common methods of generating random numbers in objective-c, and shares them with us, hoping to bring some reference value to everyone. Specifically as follows:

1), Arc4random () method : More accurate does not need to generate the immediately seed

Use the following methods:

The code for obtaining integers between 0 and x-1 via Arc4random () is as follows:

 int value = Arc4random ()% x;

The code to get an integer between 1 and X is as follows:

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

2), Ccrandom_0_1 () method : used in cocos2d , range is [0,1]

Use the following methods:

 float random = ccrandom_0_1 () * 5; [0,5]  ccrandom_0_1 () value range is [0,1]

3), Random () method : The seed should be set when initializing

Use the following methods:

Srandom ((unsigned int) time (time_t *) NULL); When initializing, set the seed.

The code in the article is available in a more detailed note, I believe it is not difficult to understand. Interested friends can test their own hands.