math.random' code example
Example 1: javascript get random number in range
function getRandomNumberBetween(min,max){
return Math.floor(Math.random()*(max-min+1)+min);
}
//usage example: getRandomNumberBetween(20,400);
Example 2: javascript random number in range
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
}