Random Integers Over an Integer Interval

The java.util.Random class has a public int nextInt() method that returns a randomly selected integer, but there is no innate method in that class to create a random number over an integer interval, say [x,y].
However, you can use the public double nextDouble() method of the Random class to obtain a random double between 0.0 and 1.0, and then project the position of the obtained double from the [0.0, 1.0] interval to the interval [x,y]. The following code shows you how:

 public static int getIntRandomOnRange(int lower, int upper) {        //obtain the number of values in your interval     int range = (upper - lower) + 1;        Random aRandom = new Random();      // get a random double between 0.0 and 1.0    double aDouble = aRandom .nextDouble();        // multiply by the range of your interval    aDouble *= range;        // add the smallest integer value of your interval    aDouble += lower;    //drop the decimal value    aDouble = Math.floor(aDouble);    // account for the case adding one may send aDouble above you interval    if (aDouble > upper) aDouble = upper;        // cast aDouble into an int and return    int anInt = (int)aDouble;    return anInt;}
Share the Post:
Share on facebook
Share on twitter
Share on linkedin


The Latest

homes in the real estate industry

Exploring the Latest Tech Trends Impacting the Real Estate Industry

The real estate industry is changing thanks to the newest technological advancements. These new developments — from blockchain and AI to virtual reality and 3D printing — are poised to change how we buy and sell homes. Real estate brokers, buyers, sellers, wholesale real estate professionals, fix and flippers, and beyond may

man on floor with data

DevX Quick Guide to Data Ingestion

One of the biggest trends of the 21st century is the massive surge in internet usage. With major innovations such as smart technology, social media, and online shopping sites, the internet has become an essential part of everyday life for a large portion of the population. Due to this internet

payment via phone

7 Ways Technology Has Changed Traditional Payments

In today’s digital world, technology has changed how we make payments. From contactless cards to mobile wallets, it’s now easier to pay for goods and services without carrying cash or using a checkbook. This article will look at seven of the most significant ways technology has transformed traditional payment methods.