Day Of Week JS Advanced

function dayOfWeek(day) {
   let week = {
    'Monday': 1,
    'Tuesday': 2,
    'Wednesday': 3,
    'Thursday': 4,
    'Friday': 5,
    'Saturday': 6,
    'Sunday': 7
   };
   if (week.hasOwnProperty(day)) {
    console.log(week[day]);
   } else {
    console.log("error");
   }
}