Arc4random_uniform random number, arc4random_uniform

Arc4random_uniform random number, arc4random_uniform

In Objective-C, there is an arc4random () function used to generate random numbers without seeds. However, this function generates a large range of random numbers and requires a modulo algorithm to limit random values, A little troublesome.

In fact, Objective-C has a more convenient random number function arc4random_uniform (x), which can be used to generate 0 ~ (X-1) random number within the range, do not need to perform modulo operation. If you want to generate 1 ~ The Random Number of x can be written as follows: arc4random_uniform (x) + 1.

 

Arc4random_uniform (interval size) + interval minimum value = random number in the interval

If it is between 1000 and 2000, it is arc4random_uniform (2000) + 1001.