How do Java arrays implement Cloneable?

From the documentation of Object#clone():

Note that all arrays are considered to implement the interface Cloneable. Otherwise, this method creates a new instance of the class of this object and initializes all its fields with exactly the contents of the corresponding fields of this object, as if by assignment; the contents of the fields are not themselves cloned. Thus, this method performs a "shallow copy" of this object, not a "deep copy" operation.

But the documentation of java.util.Arrays doesn't indicate that Arrays implements Cloneable.

How do arrays implement Cloneable?

Solution

You are confusing java.util.Arrays, a normal class that contains methods to work with arrays, and arrays themselves, which are a rather special construct in the Java language but are nonetheless objects with a synthetic class. This is this class that implements Cloneable. It also derives directly from Object. Look at the JLS page on arrays which is pretty clear on the subject.

Look for example at this code (taken from the aforementionned JLS):

class Test {
    public static void main(String[] args) {
        int[] ia = new int[3];
        System.out.println(ia.getClass());
        System.out.println(ia.getClass().getSuperclass());
    }
}

This will print:

class [I
class java.lang.Object