Rolls a variable number of dice based on a given integer argument

dice-roller.js

function rollDice (rolls) {
  var result = "Rolled " + rolls + " dice: "
  for (var i = 0; i < rolls; i++) {
      var rollNum = Math.floor((Math.random(rolls)*6)+1);
      if (i < rolls - 1)
        result += (rollNum + ", ");
      else
        result += rollNum + ".";
  }
  return result;
};


console.log(rollDice(process.argv[2]));