wrapper classes advantages - Generic

Java collections only store Objects, not primitive types; however we can store the wrapper classes.

• Java primitive types are not reference types (e.g. an int is not an Object)
• Java does generics using type-erasure of reference types (e.g. a List is really a List at run-time)

Since both of these are true, generic Java collections can not store primitive types directly. For convenience, autoboxing is introduced to allow primitive types to be automatically boxed as reference types. Make no mistake about it, though, the collections are still storing object references regardless.

Could this have been avoided? Perhaps.

• If an int is an Object, then there's no need for box types at all.
• If generics aren't done using type-erasure, then primitives could've been used for type parameters.