What are wildcards in generics?

What are wildcards in generics?

Wildcards in generics are a way to specify a range of types in Java. They allow for flexibility in type parameters.

Can you give me an example of how to use wildcards?

Sure! You can use a wildcard with the '?' symbol. For instance, List<?> can hold a list of any type.

What is the difference between upper and lower bounded wildcards?

Upper bounded wildcards use the syntax <? extends T>, allowing you to read items of type T or its subclasses. Lower bounded wildcards use <? super T>, allowing you to write items of type T or its superclasses.

When should I use wildcards?

Use wildcards when you want to write methods that can operate on a variety of types without knowing the exact type.