Why does !{}[true] evaluate to true in JavaScript?

Question

{}[true] is [true] and ![true] should be false.

So why does !{}[true] evaluate to true

Answer 1

The answers here are good, here's a breakdown in pseudo-code:

• {}['whatever'] = empty block, NewArray('whatever') = NewArray('whatever')
• {}[true] = empty block, NewArray(true) = NewArray(true)
• !{}['whatever'] = LogicalNOT(convertToBool(NewObject.whatever)) = LogicalNOT(convertToBool(undefined)) = LogicalNOT(false) = true
• ({}['whatever']) = Grouping(NewObject.whatever) = Grouping(undefined) = undefined