What is [] + [] in javascript

Question

What are the values of []+[], []+{}, {}+[], {}+{}? And How?

This my console log

>{} + {}
>NaN
>[] + []
>\'\'
>{} + []
>0
>[] + {         


        

Answer 1

The + operator concats strings. So it attempts to convert the objects and arrays to strings.

{} converts to '[Object object]', and [] converts to ''.

EDIT: I can't explain why {} + [] is 0 and why ({}) + [] is "[object Object]".