choose a random number from 1 to 3 javascript code example

Example 1: javascript random number between 1 and 10

// Genereates a number between 0 to 1;
Math.random();

// to gerate a randome rounded number between 1 to 10;
var theRandomNumber = Math.floor(Math.random() * 10) + 1;

Example 2: javascript random number 1 or -1

//an equation that returns either 1 or -1
var number = ((Math.floor(Math.random() * 2) - 2) * 2) + 1