我怎么知道，星期几是日期？

// 获取当前日期和时间
var currentDate = new Date();

// 获取星期几的数字表示
var dayOfWeek = currentDate.getDay();

// 将数字表示转换为字符串表示
var dayOfWeekString;
switch (dayOfWeek) {
  case 0:
    dayOfWeekString = "星期日";
    break;
  case 1:
    dayOfWeekString = "星期一";
    break;
  case 2:
    dayOfWeekString = "星期二";
    break;
  case 3:
    dayOfWeekString = "星期三";
    break;
  case 4:
    dayOfWeekString = "星期四";
    break;
  case 5:
    dayOfWeekString = "星期五";
    break;
  case 6:
    dayOfWeekString = "星期六";
    break;
}

console.log("今天是" + dayOfWeekString);