https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random

random.js

// Getting a random number between 0 (inclusive) and 1 (exclusive)
function getRandom() {
	return Math.random();
}

// Getting a random number between two values
function getRandomArbitrary(min, max) {
	return Math.random() * (max - min) + min;
}

// Getting a random integer between two values
function getRandomInt(min, max) {
	min = Math.ceil(min);
	max = Math.floor(max);
	return Math.floor(Math.random() * (max - min)) + min; //The maximum is exclusive and the minimum is inclusive
}

// Getting a random integer between two values, inclusive
function getRandomIntInclusive(min, max) {
	min = Math.ceil(min);
	max = Math.floor(max);
	return Math.floor(Math.random() * (max - min + 1)) + min; //The maximum is inclusive and the minimum is inclusive 
}