Why this codE has 21 output??Is unset means object destroyed???

Question

https://www.sololearn.com/post/107296/?ref=app

Answer 1

Well, it clearly does

Answer 2

Basically a deconstructor is called after there are no references to an object. After using the unset function (not sure what it does), there were no references to the object (so garbage collection came to pick it up and the deconstructer was called)