What's the best way to automatically insert slashes '/' in date fields

Question

I\'m trying to add functionality to input date fields so as when the users enters in digits, slashes \"/\" get automatically added.

So suppose I have the following

Answer 1

This solution works for me. I have captured the blur event though you will have to change the code if you want to use keyup event. HTML

Javascript

function bar(txtBox) {
  if (txtBox == null) {
    return ''
  }

  var re = new RegExp(/(\d{6})(\d{2})?/);

  if (re.test(txtBox.value)) {
    if (txtBox.value.length == 8) {
      txtBox.value = txtBox.value.substring(0, 2) + '/' + txtBox.value.substring(2, 4) + '/' + txtBox.value.substring(4, 8)
    }
    if (txtBox.value.length == 7) {
      txtBox.value = txtBox.value.substring(0, 2) + '/' + txtBox.value.substring(2, 3) + '/' + txtBox.value.substring(3, 8)
    }

    if (txtBox.value.length == 6) {
      if (txtBox.value.substring(4, 6) < 20) {
        txtBox.value = txtBox.value.substring(0, 2) + '/' + txtBox.value.substring(2, 4) + '/20' + txtBox.value.substring(4, 6);
      } else {
        txtBox.value = txtBox.value.substring(0, 2) + '/' + txtBox.value.substring(2, 4) + '/19' + txtBox.value.substring(4, 6);
      }
    }
  }
  return txtBox.value;
}