randomNum = 0 + (int)(3*Math.random()); code example
Example: javascript get random number in range
function getRandomNumberBetween(min,max){
return Math.floor(Math.random()*(max-min+1)+min);
}
//usage example: getRandomNumberBetween(20,400);
function getRandomNumberBetween(min,max){
return Math.floor(Math.random()*(max-min+1)+min);
}
//usage example: getRandomNumberBetween(20,400);