How an array implements an interface?

Question

Section 5.5 of JLS (dealing with casting conversions) explains something like this:
When an interface type S is cast to an array type T,
"then T must implement S, or a compile-time error occurs. "
I could not understand how an array can be made to implement an interface.
I guessed it means that the component type of array implements the interface, and prepared the following test code. It doesn't compile.
interface S{  }
class C implements S{ }
class Test {
public static void main(String[] args) {
     C[] ac = new C[100];
     S s = new C();
     C[] ac1 = (C[])s; //doesn't compile
     System.out.println(ac1.length);
Would someone open my eyes? Thank you

Answer 1

dmbdmb Your correction compiled my code. But I was not looking for that, because the corrected code casts an array type to array type. Anyway, thanks.
jverdYou are the man. Now I got it. Thank you.
I think I will have to remember your simplified rule (Then S must be Serializable or Cloneable) rather than the JLS' rule. With your rule, I can write a test code like this, which compiles, and which shows that an interface type can be cast to array type.
import java.awt.Point;
import java.io.Serializable;
class Test {
        public static void main(String[] args) {
           Point[] pa = new Point[100]; //any array of reference type
           Serializable s = new String("test");
           Point[] pa1 = (Point[])s; //compiles, though invalid at runtime
}