re: Handling Array Duplicates Can Be Tricky VIEW POST


I'd just use JSON.stringify(obj) when comparing objects. Of course it all depends on the things you're trying to compare, but that is really the most simple way if you have a structured data set. Perhaps a performance expert can tell us if this method is expensive though!


I'm no expert, but you will loose some item in your array (every non serializable like functions), it will fail on non utf8 encoded string, throws on circular reference and order will matter.

Overall, JSON is not a great way to compare complex object or array.


Agreed, it's not great in most cases. However, sometimes it is just practical from a dev productivity point of view:

  • writing your own datastructure-comparison will introduce more error sources, especially if you need to refactor. So writing your own is only economical on frequently used code
  • order: using service workers or persisting to localStorage means your data structure will "exit" the JavaScript VM's context. Then you definitely shouldn't use it. If you always generate it the same way in the same runtime context, you're safe(r)
  • it can have better performance than other comparison algorithms, especially on smaller datasets
  • Sometimes you don't want to have functions in your objects, by design. E.g. when using redux. Here it's also safe(r)

If you use it, wrap it in your own compareXYZ() util-function, so you can
a) adjust it later
b) see that function in your profiler pop up

code of conduct - report abuse