interface statement

interface InterfaceName [extends InterfaceName ] {}

(in top-level package .as files Ia, B, C, Ib, D, Ic, E) 
// filename Ia.as 
interface Ia { 
 function k():Number; // method declaration only 
 function n(x:Number):Number; // without implementation 
} 
// filename B.as 
class B implements Ia { 
 function k():Number {
 return 25;
 } 
 function n(x:Number):Number {
 return x + 5;
 } 
} // external script or Actions panel // script file 
var mvar:B = new B(); 
trace(mvar.k()); // 25 
trace(mvar.n(7)); // 12 
// filename c.as 
class C implements Ia { 
 function k():Number {
 return 25;
 } 
} // error: class must implement all interface methods 
// filename Ib.as 
interface Ib { 
 function o():Void; 
} 
class D implements Ia, Ib { 
 function k():Number {
 return 15;
 } 
 function n(x:Number):Number {
 return x * x;
 } 
 function o():Void {
 trace("o");
 } 
} // external script or Actions panel // script file 
mvar = new D(); 
trace(mvar.k()); // 15 
trace(mvar.n(7)); // 49 
trace(mvar.o()); // "o" 
interface Ic extends Ia { 
 function p():Void; 
} 
class E implements Ib, Ic { 
 function k():Number {
 return 25;
 } 
 function n(x:Number):Number {
 return x + 5;
 } 
 function o():Void {
 trace("o");
 } 
 function p():Void {
 trace("p");
 } 
}