如何将MM/DD/YYYY转换成YYYY-MM-DD？

function formatDate(dateString) {
  var dateArray = dateString.split("/");
  var month = dateArray[0];
  var day = dateArray[1];
  var year = dateArray[2];
  
  var formattedDate = year + "-" + month + "-" + day;
  return formattedDate;
}

var inputDate = "12/25/2022";
var formattedDate = formatDate(inputDate);
console.log(formattedDate);  // 输出：2022-12-25