function random Number(and) { return Math.floor(Math.random() * n); } meaning 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: Math.random javascript double

function getRandomNumberBetween(min,max){
    return Math.floor(Math.random()*(max-min+1)+min);
}