我需要一个code仅生成随机偶数2-100 有生成随机数在网络上的教程，但他们是奇数和偶数。 请理解我只需要连号产生。

I need a code to generate only random EVEN numbers 2-100 There is tutorials on the web that generate random numbers but they're odd and even. Please understand i just need even numbers to generate.

推荐答案

这将工作：

NSInteger evenNumber = (arc4random_uniform(50) + 1) * 2;

arc4random_uniform（50）将范围为0得出的结果 - 49加1给出了一个范围值1 - 50乘法由两个给你，即使在数的范围内。2 - 100

arc4random_uniform(50) will give results in the range 0 - 49. Adding 1 gives a value in the range 1 - 50. Multiplying by two gives you even numbers in the range 2 - 100.