So far i have changed the date format from "24 Feb 2014" to "Feb-24-2014" using:

    var dateStart = date;
    var arr = dateStart.split(' ');
    console.log(arr[1]+"-"+arr[0]+"-"+arr[2]);

How would I extract the month from arr[1] and replace its equivalent numerical value?

(WHAT i'VE TRIED: I've created an array and an each function to loop through this array and return the month names values (i.e, 2 from Feb, 5 from May)).

ANSWER: The bit that I was looking for specifically in my case was creating the split "arr[1]" as an indexer for the dateArray:

dateArray[arr[1]]

So far i have changed the date format from "24 Feb 2014" to "Feb-24-2014" using:

    var dateStart = date;
    var arr = dateStart.split(' ');
    console.log(arr[1]+"-"+arr[0]+"-"+arr[2]);

How would I extract the month from arr[1] and replace its equivalent numerical value?

(WHAT i'VE TRIED: I've created an array and an each function to loop through this array and return the month names values (i.e, 2 from Feb, 5 from May)).

ANSWER: The bit that I was looking for specifically in my case was creating the split "arr[1]" as an indexer for the dateArray:

dateArray[arr[1]]

• javascript
• jquery

• create a array of months and do lookup – Raghunandan Krishnamurthy Commented Feb 6, 2014 at 10:10
• If you're trying to get the month from a string then just use new Data(dateString).getMonth() + 1; – Reinstate Monica Cellio Commented Feb 6, 2014 at 10:11
• possible duplicate of Easiest way to convert month name to month number in JS ? (Jan = 01) – Faust Commented Feb 6, 2014 at 10:12
• See: stackoverflow./questions/13566552/… – Faust Commented Feb 6, 2014 at 10:13
• Are the month strings going to be in the current locale's language, or a fixed language? If you can't guarantee that the current locale is the same as used by the month strings then beware of any solution using a Date object! – Alnitak Commented Feb 6, 2014 at 10:15

6 Answers 6

Use a hash - like that you don't have to iterate over an array.

 var dateHash = {
    Jan : 1,
    Feb: 2,
    Mar: 3,
    Apr: 4,
    May: 5,
    Jun: 6,
    Jul: 7,
    Aug: 8,
    Sep: 9,
    Oct: 10,
    Nov: 11,
    Dec: 12
   };

var newDate = dateHash[arr[1]]+"-"+arr[0]+"-"+arr[2];

You could keep an object of key/value pairs where the key is the month name and the value is the month number:

var months = {
    January: 1,
    February: 2,
    ...
};

and then:

var monthNumber = months['April'];

or:

Reference Converting month name to month number using JavaScript

use:

var i;
  for (i = 0; i < arr.length; ++i) {
    alert(new Date(Date.parse(arr[i] +" 1, 2012")).getMonth()+1);
}

demo

Just for fun I did this:

function getMonthFromString(mon){
   return new Date(Date.parse(mon +" 1, 2012")).getMonth()+1
}

Bonus: it also supports full month names :-D Or the new improved version that simply returns -1 - change it to throw the exception if you want (instead of returning -1):

function getMonthFromString(mon){

   var d = Date.parse(mon + "1, 2012");
   if(!isNaN(d)){
      return new Date(d).getMonth() + 1;
   }
   return -1;
 }

Source : HERE

To transform month into number:

var dateString = "24 Feb 2014";
var date = new Date(dateString)
var result = date.getMonth() + 1 + "-" + date.getDate() + "-" + date.getFullYear()
console.log(result)

To transform number into month:

var dateString = "24-2014";
var monthNumber = 2;
var months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
var result = months[monthNumber - 1] + "-" + dateString
console.log(result)

var month=new Array(12);
        month[0]="Jan";
        month[1]="Feb";
        month[2]="Mar";
        month[3]="Apr";
        month[4]="May";
        month[5]="Jun";
        month[6]="Jul";
        month[7]="Aug";
        month[8]="Sep";
        month[9]="Oct";
        month[10]="Nov";
        month[11]="Dec";

month[mm] === value!!