How to get a random number from a specific range in JavaScript

1. Introduction

In this article, we will present a method to generate random numbers from a specific range in JavaScript.

2. Get a random float number between min and max value

In general, to get a random number in JavaScript we will have to use Math.random() a method that returns a floating-point, pseudo-random number in the range 0–1. The following example shows how to generate a random float number:

const randomFloat = (min, max) => Math.random() * (max - min) + min;

console.log(randomFloat(1, 100));

3. Get a random int value

Generating a random int number requires Math.floor() method that will return the largest integer less than or equal to a given number. The following snippet generate random integer value between min and max range:

const randomInt = (min, max) => Math.floor(Math.random() * (max - min + 1) + min);

console.log(randomInt(1, 100));

4. Get a random boolean value

If we want to generate random boolean value (true/false) we can also use Math.random() method and simply return true if the result is greaten or equal 0.5. Check the following example:

const randomBool = () => Math.random() >= 0.5;

console.log(randomBool());

5. Conclusion

In this article, we present how to generate random float and int value using specified min-max range, and also a random boolean value. In all these cases we used JavaScript Math.random() the method that generates a pseudo-random number.