Javascript日期对象月份转换

function convertMonthName(month) {
  var monthNames = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
  return monthNames[month];
}

var date = new Date();
var month = date.getMonth();
var monthName = convertMonthName(month);
console.log(monthName);

function convertMonthIndex(monthName) {
  var monthIndex = {
    "January": 0,
    "February": 1,
    "March": 2,
    "April": 3,
    "May": 4,
    "June": 5,
    "July": 6,
    "August": 7,
    "September": 8,
    "October": 9,
    "November": 10,
    "December": 11
  };
  return monthIndex[monthName];
}

var monthName = "January";
var monthIndex = convertMonthIndex(monthName);
var date = new Date();
date.setMonth(monthIndex);
console.log(date.getMonth());