Difference between != null and !== null in Javascript

Asked Mar 04 '13 at 18:58

Active Mar 04 '13 at 19:09

Viewed 68 times

Splitting hair here, but my editor complains I should use a !== null instead of a != null in a Javascript if statement. What is the difference?

Update

This question has been closed as duplicate, but the other questions supposedly answering my question are not answering it... Check their answers! There is a subtlety here -> null

edited Mar 04 '13 at 19:09

asked Mar 04 '13 at 18:58

Jérôme Verstrynge

51,859
84
263
429

1

That compairs also the type. However I'm not sure why this should be important for null – rekire Mar 04 '13 at 19:00
1

`!=` compare value, `!==` compares value AND type. – Rocket Hazmat Mar 04 '13 at 19:00
7

@rekire because `undefined==null` but `undefined!==null` – nbrooks Mar 04 '13 at 19:00
@nbrooks ah I see... `typeof(undefined)=="undefined"` and `typeof(null)=="object"`. – rekire Mar 04 '13 at 19:01
1

I think nbrooks comment deserves a real answer... – Jérôme Verstrynge Mar 04 '13 at 19:10
http://stackoverflow.com/questions/2703102/typeof-undefined-vs-null – Bergi Aug 27 '16 at 16:56

Difference between != null and !== null in Javascript

0 Answers0