# How do I create random number?

The `java.lang.Math.random()` method returns random number between `0.0` and `1.0` including `0.0` but not including `1.0`. By multiplying `Math.random()` result with a number, for example `10` will give us a range of random number between `0.0` and `10.0`.

To get a random number between two numbers (`n` and `m`) we can use the formula of: `n + (Math.random() * (m - n))`. Where `n` is the lowest number (inclusive) and `m` is the highest number (exclusive).

``````package org.kodejava.example.lang;

public class RandomNumberExample {
public static void main(String[] args) {
// The Math.random() returns a random number between 0.0 and 1.0
// including 0.0 but not including 1.0.
double number = Math.random();
System.out.println("Generated number: " + number);

// By multiplying Math.random() result with a number will give
// us a range of random number between, for instance 0.0 to 10.0 as
// shown in the example below.
number = Math.random() * 10;
System.out.println("Generated number: " + number);

// To get a random number between n and m we can use the formula:
// n + (Math.random() * (m - n)). The example below creates random
// number between 100.0 and 200.0.
int n = 100;
int m = 200;
number = n + (Math.random() * (m - n));
System.out.println("Generated number: " + number);

// Creates an integer random number
int random = 100 + (int) (Math.random() * 100);
System.out.println("Generated number: " + random);
}
}
``````

Here is an example result of our program.

``````Generated number: 0.670447515721026
Generated number: 5.118459516569203
Generated number: 139.89504952544274
Generated number: 158
``````

### Wayan Saryada

Founder at Kode Java Org
I am a programmer, a runner, a recreational diver, currently live in the island of Bali, Indonesia. Mostly programming in Java, Spring Framework, Hibernate / JPA. You can support my works by donating here. Thank you ?

## 1 Comments

1. Thank you very much! It’s helpful.

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