JavaScript: get a random number from a specific range

random.js

/**
 * Get a random floating point number between `min` and `max`.
 * 
 * @param {number} min - min number
 * @param {number} max - max number
 * @return {number} a random floating point number
 */
function getRandomFloat(min, max) {
  return Math.random() * (max - min) + min;
}

/**
 * Get a random integer between `min` and `max`.
 * 
 * @param {number} min - min number
 * @param {number} max - max number
 * @return {number} a random integer
 */
function getRandomInt(min, max) {
  return Math.floor(Math.random() * (max - min + 1) + min);
}

/**
 * Get a random boolean value.
 * 
 * @return {boolean} a random true/false
 */
function getRandomBool() {
  return Math.random() >= 0.5;
}

One-liner versions for anyone that's interested:

const getRandomFloat = (min, max) => Math.random() * (max - min) + min;
const getRandomInt = (min, max) => Math.floor(Math.random() * (max - min + 1) + min);
const getRandomBool = () => Math.random() >= 0.5;

Very usefull, thank you ...

One modification could be done with ES6 default parameters to allow it to take either one or two args.

function random(n, b = 0) {
    return Math.random() * (b-n) + n;
}

I want to print random number between 70 t0 100..

I want to print random number between 70 t0 100..

const number = getRandomInt(70, 100);

I want to print random number between 70 t0 100..

const number = getRandomInt(70, 100);

that's not working ... what is getRandomInt? there is no any predefined function of getRandomInt.. i tried Math.floor(Math.random*100);
but that wat i received 1 to 100 but I just need 70 to 100..

One-liner versions for anyone that's interested:

const getRandomFloat = (min, max) => Math.random() * (max - min) + min;
const getRandomInt = (min, max) => Math.floor(Math.random() * (max - min + 1) + min);
const getRandomBool = () => Math.random() >= 0.5;

can you expand this so we can easily understand line liner short code and long code like 1 vs 2

Really helpful, thanks!

I know this isn't recent but any tips on actually getting random numbers when a button calls this function often? I was using this to get some random results and the page displays repeats even after refreshing and reloading everything.

Thanks, I needed it

Random boolean method can also be implemented so:

function getRandomBool() {
  return !!Math.round(Math.random());
}

Thanks dude, its work on my machine