Write a function that converts user entered date formatted as M/D/YYYY to a format required by an API (YYYYMMDD)

Question

Write a function that converts user entered date formatted as M/D/YYYY to a format required by an API (YYYYMMDD). The parameter "userDate" and the return value are strings. For example, it should convert user entered date "12/31/2014" to "20141231" suitable for the API. i tried:

function formatDate(userDate) {
  // format from M/D/YYYY to YYYYMMDD
  a = new Date(userDate);
  y = a.getFullYear();
  m = a.getMonth();
  d = a.getDate();
  return y.toString() + m.toString() + d.toString();
}

console.log(formatDate("12/31/2014"));

where is the problem??

I'm pretty sure the constructor for `Date` doesn't expect a string in an arbitrary format, so there's that. — Federico klez Culloca, Jan 08 '18 at 12:06
Think about what happens when the month (or day) is less than 10. Also, `Date.prototype.getMonth` returns a month index from 0 to 11 for reasons. — Ry-, Jan 08 '18 at 12:06
Have you considered just using ``? It returns a date in `Y-m-d` format, which is unambiguous, and for your API (which is weird) you can just strip the `-`s and you're done. — Niet the Dark Absol, Jan 08 '18 at 12:06
And if this is homework where you solution gets rejected, why not say so? It might be obvious to you, but we can't read your mind. — , Jan 08 '18 at 12:08
getMonth returns a value between 0 and 11, other than that your code works, and you will need to take the input of @Ryan into account. — rolfv1, Jan 08 '18 at 12:08
https://stackoverflow.com/questions/32192922/how-do-i-get-a-date-in-yyyy-mm-dd-format — Dalton Cézane, Jan 08 '18 at 12:09
If it's a definite fixed format string then just split it and use the values from that. — Reinstate Monica Cellio, Jan 08 '18 at 12:10

score 3 · Answer 1 · answered Jan 08 '18 at 12:16

String#split() the date on / and then concat the generated date, month and year.

function AddLeadingZero(num) {
  return (num < 10 ? '0' : '') + num;
}

function formatDate(userDate) {
  var [month, day, year] = userDate.split('/');
  return year + AddLeadingZero(month) + AddLeadingZero(day); 
}

console.log(formatDate("12/31/2014"));
console.log(formatDate("10/1/2014"));

score 3 · Accepted Answer · edited Jan 08 '18 at 13:00

3

The issue is that getMonth() returns a month index from 0 to 11, so December appears as 11 and not 12.

edited Jan 08 '18 at 13:00

Madara's Ghost

172,118
50
264
308

answered Jan 08 '18 at 12:26

Meital Weiss

46
5

score 0 · Answer 3 · answered Jan 08 '18 at 12:12

0

var convertDate = function(usDate) {
  var dateParts = usDate.split(/(\d{1,2})\/(\d{1,2})\/(\d{4})/);
  return dateParts[3] + dateParts[1] +  dateParts[2];
}

var inDate = "12/31/2014";
var outDate = convertDate(inDate);

alert(outDate);

answered Jan 08 '18 at 12:12

pravin dabhi

302
1
11

Write a function that converts user entered date formatted as M/D/YYYY to a format required by an API (YYYYMMDD)

3 Answers3