What are wildcards in Java generics?

Can you explain what wildcards are in Java generics?

Sure! Wildcards in Java generics are represented by the question mark (?) and are used to denote an unknown type.

What are the different types of wildcards?

There are three types of wildcards: unbounded wildcards, bounded wildcards (upper and lower), and wildcard with bounds.

Can you give me an example of each type?

Of course! An unbounded wildcard is simply <?>, an upper bounded wildcard is <? extends T>, and a lower bounded wildcard is <? super T>.

When should I use wildcards?

Use wildcards when you want to relax the restrictions on a generic type, allowing for more flexibility in method parameters.