calling a static method of a class with only an instance

Question

If all I have is an instance of an object, can I call a static method of its class? For fun, let's say I don't know what the name of the class is, only the name of the static method.

Can I do this? How do I do this?

score 7 · Accepted Answer · edited Dec 14 '12 at 18:04

7

You can use the Object's constructor property to get a reference to that object's class object, you can then call the static variable from that class object

    package{
        import flash.display.Sprite;

        public class Test extends Sprite{

            public function Test(){
                var variable : A = new A();
                trace((variable as Object).constructor.a());

            }
        }
    }
    class A{
       static function a() : String{
           return "test";
       }
    }

edited Dec 14 '12 at 18:04

T.W.R. Cole

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answered Jul 27 '09 at 21:41

SquareRootOf2

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Keep in mind that the constructor property does not work on some Proxy-based classes like XML and XMLList. – Richard Szalay Jul 28 '09 at 21:47
trivally edited to more perfectly answer the question being asked – T.W.R. Cole Dec 14 '12 at 17:55

score 5 · Answer 2 · answered Jul 28 '11 at 06:44

5

There is a simpler way, but this assumes that the static functions exists.

var myclass:Class = getDefinitionByName("MyClass") as Class;
myclass["myStaticMethod"]();

It kinda surprised me that this syntax works.

answered Jul 28 '11 at 06:44

loungerdork

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It won't pass the compiler. 1180: Call to a possibly undefined method myStaticMethod. – loungerdork May 08 '14 at 13:57

score 1 · Answer 3 · edited May 23 '17 at 12:01

1

Get the class reference by it's instance.

var className:string = getQualifiedClassName(object); //returns the class name    
var classObj:Class = getDefinitionByName(className) as Class; //get a Class object

Also see this - How to get type of variable? and instantiate it?

edited May 23 '17 at 12:01

Community

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answered Jul 27 '09 at 21:33

Chetan S

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Just realized that you probably can't call a static method even with a reference to the Class object. I guess this answer is only halfway there. I don't have access to flex compiler, sorry. – Chetan S Jul 27 '09 at 21:43
Yes, you can, check out my answer above. – loungerdork Jul 28 '11 at 06:54

calling a static method of a class with only an instance

3 Answers3