Flash / Flex / ActionScript/Function/return

Assign value returned from a function to a variable

 
package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        var color:String = getColor();
        trace(color); // Displays: Red

    } 
    function getColor():String {
         var color:String = "Red";
         return color;
         color = "Blue";
         return color;
    }
  }
}

Defining a Return Type for Your Function

 
package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
         var myObject:* = createObject("Array");
         myObject.push(1, 2, 3, 4, 5);
        
         trace(myObject); //Displays: 1, 2, 3, 4, 5
    }
    function createObject(type:String):* {
         switch (type) {
             case "Boolean": return new Boolean ();
             case "Number": return new Number ();
             case "String": return new String ();
             case "Array": return new Array ();
             default: trace("Unknown type"); return null;
         }
     }
  }
}

If you attempt to actually return a value in a void method, the compiler generates an error.

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

    }
    private function sampleMethod (  ):void {
      return "some value";  // This causes the compiler to generate an error.
    }
  }
}

Obtaining the Result of a Method: use a return statement that specifies the value to return.

 
package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        var playerScore:Number = average(6, 10);
        trace("The player"s average score is " + playerScore);

    }
    private function average (a:Number, b:Number):Number {
      return (a + b)/2;
    }
  }
}

Returning void: If you don"t need your function to return anything, simply use a return type of void.

 
package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        doNothing(); 
    }
    function doNothing ():void {
    
    } 
  }
}

Return value from function

 
package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        trace(getCircumference(25)); // Displays: 78.53981633974483

    }
    function getCircumference (diameter:Number):Number {
        var circumference:Number = diameter * Math.PI;
        return circumference;
    }
  }
}

The return statement exits the current method

 
package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        sampleFunction(  );
    }
    private function sampleFunction (  ):void {
      return;
      trace("Never called");
    }
  }
}

Use a return statement to exit a method under certain conditions

 
package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        checkPassword("M");
        checkPassword("S");
    }
    private function checkPassword (password:String):void {
      if (password != "S") {
        return;
      }
      trace ("T");
    }
  }
}

Use the return value of a method, without storing it in a variable, by passing it as a parameter to another function

 

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

        trace("The player"s average score is " + average(6, 10));

    }
    private function average (a:Number, b:Number):Number {
      return (a + b)/2;
    }
  }
}