How to Generate Random Numbers in a Range in Java
Random numbers are used in a number of programming applications such as games, computer simulation, cryptography etc. It is also used to generate test data. Usually you want to generate random numbers in a specific range of values. The following example program in Java generates 5 random numbers between 10 and 20 (both inclusive).
import java.util.concurrent.ThreadLocalRandom; /** * Prints random numbers within a range of values inclusive of boundary values. * For example, if the range is 10 to 20, this program will print random numbers * which will be between 10 and 20 including 10 and 20. */ public class RandomInRange { public static void main(String[] args) { // We want numbers to vary from 10 to 20 including 10 and 20. int minValueForRange = 10; int maxValueForRange = 20; // create 5 random numbers and then print them for(int i=0;i<5;i++) { int randomNumber = ThreadLocalRandom.current().nextInt(minValueForRange, maxValueForRange + 1); System.out.println(randomNumber); } } }
If you want random floating point values or long values you can use nextDouble() or nextLong() methods of ThreadLocalRandom.