Rearrange date fromat

Question

Is there a better way to write this code? I'm taking a "date" parameter (which is a string in this case) thats formatted in one of two ways mm/dd/yy' or m/d/yy and I need to reformat it to look like this yyyymmdd

functionName = function(date){

  var month = "", day = "", year = "";

  if(!date.length) return;
  else {        
    date.slice(0, 2) < 10 ? month = '0' + date.slice(0, 2) : month = date.slice(0, 2);
    date.slice(3, 5) < 10 ? day = '0' + date.slice(3, 5) : day = date.slice(3, 5);
    year = "20" + date.slice(6, 8); 
  }
  return year + month + day;
}

Also how should I check to see if the date was in the 1900's and format it accordingly?

It is impossible to know the difference between 1920 and 2020 with those formats, both will be '/20'. If possible, better to change the format of the "date" that you are receiving instead of trying to rearrange. — Ariel, Jul 09 '21 at 19:19
Please check this https://stackoverflow.com/questions/5619202/converting-a-string-to-a-date-in-javascript — SRK45, Jul 09 '21 at 19:35

score 0 · Answer 1 · answered Jul 09 '21 at 22:20

There is no way to make a full year from a two digit year, it's missing information.

However you could simplify your function using .split() and .padStart()

function FormatDate (date) {
  if (date) {
    date = date.split('/'); //date[0] = month, date[1] = day, date[2] = year
    return date[2] + date[0].padStart(2, '0') + date[1].padStart(2, '0');
  }
}

console.log(FormatDate('07/09/20')); //outputs 200709

Rearrange date fromat

1 Answers1