Sign up to request clarification or add additional context in comments. ... For the sake of completeness, when you say 'complete', do you mean including min and excluding max? 2014-01-29T11:00:28.897Z+00:00 ... Your formula generates numbers between min and min + max. Random random = new Random(1234567); int min = 5; int max = 20; while (true) { int x = (int)(Math... More on stackoverflow.com

Find centralized, trusted content ... you use most. Learn more about Collectives ... Bring the best of human thought and AI automation together at your work. Explore Stack Internal ... class in Java. (And) I was wondering about the class. For example, I'm trying to write a dice game that needs random numbers from 1 to 6 each "roll". This is where math.random( ) ... More on stackoverflow.com

See computational methods under: https://en.wikipedia.org/wiki/Random_number_generation Pseudo-random typically means there's an algorithm for generating the numbers that have certain probability distributions. This algorithm usually has some initial "seed" number. Given a seed, it produces the same sequence of random numbers (hence pseudo-random). For some applications, pseudo-random is good enough (esp. since you can repeatedly test the same values). More on reddit.com

I always use Random. The reason is that if a class depends on random number generation, it actually has a dependency on another thing whose job it is to generate random numbers (you could even make the argument this is a hidden I/O operation). It's damn near impossible to write a unit test against a class or method that calls a global function because you have no access to mock out the response for that function within a test. This is even more the case for classes that rely on randomly generated numbers. Passing a Random into a class that needs access to random numbers makes it easy to unit-test that class, as well as substitute in alternative RNG as needed, for example using SecureRandom which implements the Random interface, providing a more even distribution of generated numbers at the cost of speed. Random number generators, at least in Java, tend to mutate state internally - which is dangerous for multi-threaded programming. You want to minimize the amount of state mutation in a program to enable multi-threading, and Random turns the mutable state for random number generation to be scoped to an object rather than to the entire global space as Math.random() does. Other benefits of using Random over Math.random(): You can pass a single instance of Random into the first class that needs the ability, and pass the same instance around into lower classes as they require it as well. This means that, on your program runs, if you output the seed number somewhere like into a log or temporary file, you can seed your program with the same seed value and generate exactly the same behavior, deterministically. This makes debugging issues that arise in your program much easier. The Random interface is superior, allowing you to request random booleans, byte sequences, doubles, floats, longs, and ints. It also allows you to request a random int within a specific range. All of these let you avoid inserting the same boilerplate math that uses a Math.random(). More on reddit.com