Doubt abt Serializable,Set,Cloneable Interface

Question

WE know that Serializable,Set,Cloneable Interface have no
members.But by Implementing this the classes get some Features .
example a class can get Serializability by implementing the java.io.Serializable interface.
How it is Possible ? Tell me some Idea?

Answer 1

WE know that Serializable,Set,Cloneable Interface
have no
members.But by Implementing this the classes get some
Features .
example a class can get Serializability by
implementing the java.io.Serializable interface.
How it is Possible ? Tell me some Idea?Serializable is just a "marker interface." It doesn't declare any methods. It's just a flag that other methods can check. DataOutputStream.writeObject checks whether the class implements Serializable, and throws and excpetion if it doesn't.
Likewise Cloneable.
For "normal" interfaces, like Set, you get the behavior by implementing the methods. For example Set specifies and add(Object obj) method. If you implement a Set, you must create and implement that method. If you don't, the code won't compile. What you do inside that method is entirely up to you. For it to be correct, its behavior must follow the interface's docs, but the compiler can't check that.