Math.random

• Math.random()
  • Range: 0 ⇐ x < 1

let randomNumber = Math.random() * 6

• Range is 0 ⇐ x < 6

• With range

 
function getRandomArbitrary() {
  let result = Math.random() * (max - min) + min;
  return Math.round(result);
}

• Example: 1-13

function getRandomCard() {
  return Math.floor(Math.random() * 13) + 1;
}