Flash / Flex / ActionScript/Function/function variable

A method assigned to a variable can be invoked via that variable using the standard parentheses operator, ( ).

   <source lang="java">

package{

 import flash.display.Sprite;
 
 public class Main extends Sprite{
   public function Main(){
   var consume = eat;
   consume();

   }
   public function eat () {
     trace("eat");
   }    
 }

}

       </source>
   
  

Bound Methods, which is treated as a value

   <source lang="java">

package{

 import flash.display.Sprite;
 
 public class Main extends Sprite{
   public function Main(){
   var consume = eat;
   }
   public function eat (calories) {
     trace("eat");
   }
 }

}

       </source>
   
  

Creating Anonymous Functions

   <source lang="java">

//Here is the syntax for an anonymous function: /* function():datatype {

 statements

};

• /

package{

 import flash.display.Sprite;
 
 public class Main extends Sprite{
   public function Main(){
       var fSayHi:Function = function(sName:String):void {
         trace("Hi, " + sName);
       };
       fSayHi("Joey"); 
   }
 }

}

       </source>
   
  

Function type variable

   <source lang="java">

package{

 import flash.display.Sprite;
 
 public class Main extends Sprite{
   public function Main(){
     var fFactorial:Function  = function(nOperand:Number):Number{
             if(nOperand > 0){
               return nOperand * arguments.callee(nOperand-1);
             }
             else{
               return 1;
             }
     }
     fFactorial(2);
   }
 }

}

       </source>
   
  

Referencing Functions

   <source lang="java">

package{

 import flash.display.Sprite;
 
 public class Main extends Sprite{
   public function Main(){

       var fArea:Function = calculateArea;
       trace(fArea(6, 6));
   }
   function calculateArea(a:Number, b:Number):Number {
     var nArea:Number = a * b;
     return nArea;
   }
 }

} // 36

       </source>