Filter array of objects with another array of objects

Question

This question is similar to this one Jquery filter array of object with loop but this time I need to do the filter with an array of objects.

Exemple:

I have

Answer 1

If at all a filter like this is required I would propose to create a dictionary (object) whose key is hash of attributes which defines a match (in this case userid & projectid) that way you need to iterate over 1st dict(haystack) to check if key is available in 2nd dict (needle). Hope this helps.