Format date to MM/dd/yyyy in JavaScript [duplicate]

Question

Try this; bear in mind that JavaScript months are 0-indexed, whilst days are 1-indexed.

var date = new Date('2010-10-11T00:00:00+05:30');
    alert(((date.getMonth() > 8) ? (date.getMonth() + 1) : ('0' + (date.getMonth() + 1))) + '/' + ((date.getDate() > 9) ? date.getDate() : ('0' + date.getDate())) + '/' + date.getFullYear());

All other answers don't quite solve the issue. They print the date formatted as mm/dd/yyyy but the question was regarding MM/dd/yyyy. Notice the subtle difference? MM indicates that a leading zero must pad the month if the month is a single digit, thus having it always be a double digit number.

i.e. whereas mm/dd would be 3/31, MM/dd would be 03/31.

I've created a simple function to achieve this. Notice that the same padding is applied not only to the month but also to the day of the month, which in fact makes this MM/DD/yyyy:

function getFormattedDate(date) {
  var year = date.getFullYear();

  var month = (1 + date.getMonth()).toString();
  month = month.length > 1 ? month : '0' + month;

  var day = date.getDate().toString();
  day = day.length > 1 ? day : '0' + day;
  
  return month + '/' + day + '/' + year;
}

---

Update for ES2017 using String.padStart(), supported by all major browsers except IE.

function getFormattedDate(date) {
    let year = date.getFullYear();
    let month = (1 + date.getMonth()).toString().padStart(2, '0');
    let day = date.getDate().toString().padStart(2, '0');
  
    return month + '/' + day + '/' + year;
}

ISO compliant dateString

If the dateString is RFC282 and ISO8601 compliant:
pass the string into the Date Constructor:

const dateString = "2020-10-30T12:52:27+05:30"; // ISO8601 compliant dateString
const D = new Date(dateString);                 // {object Date}

from here we can extract the desired values by using Date Getters:

D.getMonth() + 1  // 10 (PS: +1 since Month is 0-based)
D.getDate()       // 30
D.getFullYear()   // 2020

---

Non-standard date string

If non-standard date string:
destructure the string into known parts, and than pass the variables to the Date Constructor:

new Date(year, monthIndex [, day [, hours [, minutes [, seconds [, milliseconds]]]]])

const dateString = "30/10/2020 12:52:27";
const [d, M, y, h, m, s] = dateString.match(/\d+/g);

// PS: M-1 since Month is 0-based
const D = new Date(y, M-1, d, h, m, s);  // {object Date}


D.getMonth() + 1  // 10 (PS: +1 since Month is 0-based)
D.getDate()       // 30
D.getFullYear()   // 2020