As all the member variables of java LinkedList is transient, what will be the use of implementing Serializable?

Question

1) In LinkedList implementation all the 3 member varaibles size, first, last are transient, then what is the use of implementing serializable?

2) What will be persisted when we try to serialize a LinkedList?

Answer 1

You'll notice LinkedList has writeObject and readObject methods. These write/read the size of the list and write/read each object in the list.

Note that these methods (but also the fields) are private so the implementation may change. Don't depend on it. Depend on the interfaces.