JS将带有日期名称的数组转换为日期编号

Question

将日期名称转换为日期位置的最佳方法是什么。

我有数组：

var days = ['Monday','Sunday','Friday']

如何转换为： newArray = [0,6,4]

我试试这个：

function getClosedDates() {
         var url = "/getClosedDates"; // the script where you handle the form input.
         var WEEKDAYS = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'];
var newArray = [];
var days = [];
  $.ajax({
           type: "GET",
           url: url,
           dataType: "json",
           success: function(data)
           {

 days = data.data.ClosedDays;
newArray = days.map(function(day) {
  return WEEKDAYS.indexOf(day);
});
           }
         });
return newArray;
};

但我得到 []，空数组...为什么？

Answer 1

var WEEKDAYS = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'];

var days = ['Monday','Sunday','Friday'];

var newArray = days.map(function(day) {
  return WEEKDAYS.indexOf(day);
})