Java Generics Wildcard bounding cannot set -

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i have following classes.

public class basket<e> {     private e element;      public void setelement(e x) {         element = x;     }      public e getelement() {         return element;     } }  class fruit {} class apple extends fruit {} class orange extends fruit {}

my confusion comes when consider following cases.

basket<? extends fruit> basket = new basket<>();  basket.setelement(new apple()); // cannot set

and 

basket<fruit> basket = new basket<>();  basket.setelement(new apple()); // okay!

if ? extends fruit means can pass @ least fruit (or implements or extends), why cannot pass in apple type? cannot see difference between 2 cases if passing apple type in second case works because apple descendant of fruit...

basket<? extends fruit> not mean basket can hold object long subtype of fruit. means basket of unknown type t extending fruit. example basket<apple>, basket<orange> or basket<fruit>. because basket<orange>, can't set item apple.

basket<fruit> basket of fruit. fruit do.


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