3 ms·

The choice here is really surprising. I was half-expecting NaN, that you omitted. Is there any other instance of the standard JS library returning an error obj

• jazzyjackson 10mo ago
  I think NaN itself is a bit of an error object, especially in how it's passed through subsequent math functions, which is a different choice than throwing up. But besides that I think you're right, Invalid Date is pretty weird and I somehow never ran into it. One consequence is you can still call Date methods on the invalid date object and then you get NaN from the numeric results.
• WorldMaker 10mo ago
  The fun trick is that Invalid Date is still a Date: > let invalid = new Date('not a date') > invalid Invalid Date > invalid instanceof Date true You were half-correct on expecting NaN, it's the low level storage of Invalid Date: > invalid.getTime() NaN Invalid Date is just a Date with the "Unix epoch timestamp" of NaN. It also follows NaN comparison logic: > invalid === new Date(NaN) false It's an interesting curio directly related to NaN.
  • tyilo 10mo ago
    > Invalid Date is just a Date with the "Unix epoch timestamp" of NaN. It also follows NaN comparison logic: > > > invalid === new Date(NaN) > false This is just because a JS Date is an object and have nothing to do with the inner representation. > new Date(0) === new Date(0) false