or
Random r = new Random();
int randomInt = r.nextInt(100) + 1;
Top answer 1 of 7
553
You could use e.g. r.nextInt(101)
For a more generic "in between two numbers" use:
Random r = new Random();
int low = 10;
int high = 100;
int result = r.nextInt(high-low) + low;
This gives you a random number in between 10 (inclusive) and 100 (exclusive)
2 of 7
68
Assuming the upper is the upper bound and lower is the lower bound, then you can make a random number, r, between the two bounds with:
int r = (int) (Math.random() * (upper - lower)) + lower;
Videos
Top answer 1 of 3
324
As the documentation says, this method call returns "a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive)". This means that you will get numbers from 0 to 9 in your case. So you've done everything correctly by adding one to that number.
Generally speaking, if you need to generate numbers from min to max (including both), you write
random.nextInt(max - min + 1) + min
2 of 3
101
The standard way to do this is as follows:
Provide:
- min Minimum value
- max Maximum value
and get in return a Integer between min and max, inclusive.
Random rand = new Random();
// nextInt as provided by Random is exclusive of the top value so you need to add 1
int randomNum = rand.nextInt((max - min) + 1) + min;
See the relevant JavaDoc.
As explained by Aurund, Random objects created within a short time of each other will tend to produce similar output, so it would be a good idea to keep the created Random object as a field, rather than in a method.
Study.com
study.com › courses › business courses › business 104: information systems and computer applications
Java: Generate Random Number Between 1 & 100 - Lesson | Study.com
January 6, 2018 - In this case we generated random numbers between 1 and 100. The Random class has a method to generate a pseudo-random number, nextInt(int n) , between 0 and the specified value (n).
Java67
java67.com › 2015 › 01 › how-to-get-random-number-between-0-and-1-java.html
How to Generate Random Number between 1 to 10 - Java Example | Java67
If you are interested in learning more about ThreadLocalRandom and SecureRandom classes then I suggest reading Java Performance The Definitive Guide By Scott Oaks, he has covered them in good detail in a separate section. If you are using Math.random() function and wondering that it can only return a random number between 0.0 and 1.0, you are wrong. You can still calculate random number between 1 to 10 or between any number by using Math.random() method. In this program, we will learn how to generate a random number between 1 to 100, between 1000 to 9999 or any arbitrary minimum and maximum values.
Java2Blog
java2blog.com › home › core java › random › random number between 1 and 100 in java
Random Number Between 1 and 100 in Java - Java2Blog
October 4, 2023 - TL;DR To generate random number between 1 and 100 in java, you can use Math.random() method.
Sololearn
sololearn.com › en › Discuss › 551243 › using-random-in-java-0-to-100
Using random in Java 0 to 100 | Sololearn: Learn to code for FREE!
Examples using some methods, from 50-100. int randNum = (int)((Math.random() * (50 + 1)) + 50); OR From java.util Random rnd = new Random(); int randNum = rnd.nextInt((100-50)+1) + 50 OR From java.util.concurrent int randNum = ThreadLocalRandom.current().nextInt(50, 100 + 1); *I wrote +1 sometimes to show the number is exclusive, and showed all work.* 21st Jul 2017, 12:28 AM ·
Educative
educative.io › answers › how-to-use-the-mathrandom-method-in-java
How to use the Math.random() method in Java
return (int)(Math.random() * range) + min; } public static void main( String args[] ) { MyClass obj1=new MyClass(); // creating an object of MyClass · int rand=obj1.randomWithRange(1,100); // range is from 1 to 100 · System.out.println(rand); } } Run · Relevant Answers ·
Coderanch
coderanch.com › t › 622918 › java › convert-Math-random-generate-random
How can I convert Math.random to generate a random number between 1-1000 (Beginning Java forum at Coderanch)
For example, to generate an integer between 0 and 9, you would write: int number = (int)(Math.random() * 10); By multiplying the value by 10, the range of possible values becomes 0.0 <= number < 10.0. Using Math.random works well when you need to generate a single random number. If you need to generate a series of random numbers, you should create an instance of java.util.Random and invoke methods on that object to generate numbers. Have you tried something similar yet? ... Thanks, that helps a lot. I will try that now, I was completely clueless before. They like doing that to us in college. They give us 2 assignments to choose from. 1 that is easy and a more difficult one that involves things that we havent been thought.
Medium
medium.com › @abdurrahman22 › how-to-generate-random-numbers-between-1-to-100-in-java-5b23398f7412
How to generate random numbers between 1 to 100 in Java? | by Abdur Rahman | Medium
November 3, 2023 - This code helps you to generate random numbers in java from 1 to 100.
GeeksforGeeks
geeksforgeeks.org › java › java-math-random-method-examples
Java Math random() Method - GeeksforGeeks
December 20, 2025 - To generate random integers in a range: (int)(Math.random() * (max - min + 1)) + min ... Math.random() is not suitable for cryptographic purposes. For better randomness and control, use java.util.Random or SecureRandom.
W3Schools
w3schools.com › java › java_howto_random_number.asp
Java How To Generate Random Numbers
Math.random() returns a random ... a random number between 0 and 100, you can use the following formula: int randomNum = (int)(Math.random() * 101); // 0 to 100 ·...
Medium
medium.com › @generativeai.saif › java-random-number-generator-5-methods-explained-with-examples-bf9e53abed3c
Java Random Number Generator: 5 Methods Explained with Examples | by Saif Ali | Medium
April 6, 2025 - public class MathRandomExample ... Value: " + randomValue); // Generate a random integer between 0 and 100 int randomInt = (int)(Math.random() * 101); System.out.println("Random Integer (0-100): " + randomInt); // Generate ...
CodeGym
codegym.cc › java blog › java math › generating random numbers in java
Generating random numbers in Java
February 19, 2025 - Random number between 1 and 100: This time the number = 36 · Another way to generate random numbers in Java is by using the Math.random() method, which returns a random double value between 0.0 (inclusive) and 1.0 (exclusive).
Mkyong
mkyong.com › home › java › java – generate random integers in a range
Java - Generate random integers in a range - Mkyong.com
August 19, 2015 - Just change the values of 99,1,1 to your min and max to get your #s. If you use 99 as your max, randomly 99 + 1 will make the code generate 100, so if you really want max of 99, use 98 in this code.
DEV Community
dev.to › meenakshi052003 › generating-random-numbers-between-1-and-100-in-java-i3b
Generating Random Numbers Between 1 and 100 in Java - DEV Community
March 5, 2024 - In Java, the java.util.Random class provides a robust mechanism for generating pseudorandom numbers. This tutorial will delve into the intricacies of generating random numbers in the range of 1 to 100 using Java, covering different aspects such as basic usage, advanced techniques, and common pitfalls.
Reddit
reddit.com › r/learnjava › question about random numbers in java
r/learnjava on Reddit: Question about random numbers in java
September 14, 2016 -
int max = 100 int min = 5 int randomNum = rand.nextInt((max - min) + 1) + min;
To generate a random number in Java, why is it necessary to have the "+1" ....and in this case why the "+ min" ...this is an example from an online course Im in, and I am just a bit confused about why all these parts of the equation are necessary. What is the simplest way to generate a random number (lets say between 1 and 100) in Java? Thanks for you help and suggestions.
Blogger
javarevisited.blogspot.com › 2013 › 05 › how-to-generate-random-numbers-in-java-between-range.html
How to Generate Random Numbers in Java Between Range - Example Tutorial
August 3, 2021 - This code uses Math.random() method, ... range. If you need pseudo random number between 1 to 100, you can simply multiply output of random() method with 100 and then cast it into int for integer result. ... Though you can generate random numbers by using either ways in Java ...
GeeksforGeeks
geeksforgeeks.org › java › generating-random-numbers-in-java
Generating Random Numbers in Java - GeeksforGeeks
April 24, 2025 - // Generating random number in a specific range import java.io.*; import java.util.*; class Geeks { public static void main (String[] args) { Random r = new Random(); int max=100,min=50; System.out.println("Generated numbers are within "+ min +" to "+ max); System.out.println(r.nextInt(max - min + 1) + min); System.out.println(r.nextInt(max - min + 1) + min); System.out.println(r.nextInt(max - min + 1) + min); } } Output · Generated numbers are within 50 to 100 55 51 51 · The Math class contains various methods for performing various numeric operations such as, calculating exponentiation, logarithms etc.
LabEx
labex.io › tutorials › java-how-to-generate-random-integers-within-a-specified-range-in-java-414035
How to generate random integers within a specified range in Java | LabEx
By default, the range is from 0 ... // Example of generating a random integer between 1 and 100 Random random = new Random(); int randomInt = random.nextInt(100) + 1;...