Multiple ways to generate random numbers between two numbers in javascript

Learn multiple ways to generate random numbers between two numbers in JavaScript with examples.

For example, there are two numbers, minimum=1, and maximum=10. Random numbers between 1 and 10 are one of the numbers from the range. i.e 1,2,3,4,5,6,7,8,9,10.

There are multiple ways we can generate random numbers.

#Generate Random Numbers between two numbers with javascript?

The Math.random() function generates a random floating number between 0 and 1. It returns possible values that are zero, less than 1, and exclude 1.

It returns a float number, use Math.floor() to round the lowest number.

function getRandomNumber(min, max) {
  return Math.floor(Math.random() * (max - min + 1)) + min;
}
console.log(getRandomNumber(1, 10));

It generates a random number between 1 and 10.

Similarly, The above function is simplified using ES6 arrow functions,

Here is an ES6 code to generate random numbers.

const getRandomNumber = (min, max) =>
  Math.floor(Math.random() * (max - min + 1) + min);
console.log(getRandomNumber(1, 10));

#Generate random numbers with underscore and lodash libraries

Underscore and lodash are javascript libraries, that provide reusable utility functions.

If you already have the underscore or lodash libraries in your application, use the random(min, max) function.

Here is a syntax

random(lower, upper, float - type);

lower is a lower bound value and is optional. upper is the upper bound value. float-type is true, and returns a floating value.

A random number is inclusive of lower and upper value.

Returns a number between lower and upper value

_.random(1, 100); // returns integer number between 1 and 100
_.random(1, 1000); // returns integer number between 1 and 1000
_.random(10, true); // returns floating number between 1 and 10

#Generate random numbers with a random npm library

In Nodejs, random is an npm library that provides advanced utility functions for generating random numbers.

It returns boolean, integer, and floating random values. It uses normal and Poisson distribution using given parameters.

Here is a command to install to node application.

npm install --save random

Here is an ES5 javascript code to generate random numbers

const random = require("random");
random.int(1, 10); // 8
random.float(1, 10); // 6.3

use import with ES6 to create the random object.

import random from "random";
random.int(1, 10); // 8
random.float(1, 10); // 6.3

#Conclusion

Learn multiple ways to return random numbers and float for given lower and upper values.