Does an array implements Serializable automatically ?

[Faber Siagian]

Dear ranchers,

Does an array implements Serializable automatically ?

For instance :

class AClass {}
 
AClass[] arr = new AClass[]{new AClass()};
 
System.out.println(arr instanceof Serializable) //prints true

The result is true, but why? AClass doesn't implement Serializable but the array does.

[Sandeep Bhandari]

Because internally Arrays are objects and the class for declaring arrays can't be modified by us and we need to have arrays serialized at times and hence the designers give Arrays the power of serialization by default.

Bury that into your soul: Arrays are serializable by default.

[Milan Sutaria]

api states java.util.Arrays to be

    public class Arrays extends Object

it neither mentions of serializable or not being able to modify the arrays class by extending it. But when tested

   public class B extends Arrays 

it sure gives an error stating Arrays() have a private access in java.util.Arrays.

[marc weber]

Java arrays are not included in the API documentation, but they are described in the JLS. See JLS - 10.7 Array Members...

An array thus has the same public fields and methods as the following class:

class A<T> implements Cloneable, java.io.Serializable {...

Milan, the java.util.Arrays class in the API is not an array. It is a utility class containing static methods for working with arrays. (Its constructor is private, so it can't be instantiated from outside the class.)

[Milan Sutaria]

thanks Marc for correcting me