What are Java wrapper classes and how are they used?

What are Java wrapper classes and how are they used?

Java wrapper classes are used to convert primitive data types into objects. For example, Integer is a wrapper for int.

Can you give me an example of how to use a wrapper class?

Sure! You can use Integer to convert an int to an Integer object like this: Integer myInt = Integer.valueOf(5);

Why would I need to use wrapper classes instead of primitives?

Wrapper classes are useful when you need to work with collections, as they can store objects, while primitives cannot.

Are there any performance issues with using wrapper classes?

Yes, using wrapper classes can introduce overhead due to boxing and unboxing, which can affect performance in large-scale applications.