Get the level of a hierarchy

Question

I have an array of objects, Where each object has an id and a ParentId property (so they can be arranged in trees). They are in no particular order

Answer 1

Here is your working code. Level starts at 2.

ALERT: If a level cannot be calculated, the application may go into an infinite loop. So, make sure the parentId is valid for all objects and at least one of them have parentId="id-1".