Flash / Flex / ActionScript/Array/Array Index

Adding New Elements with the length Variable

   <source lang="java">

package{

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

       var colors = ["green", "red", "blue"];
       
       colors.length = 50;
       
       trace(colors); // green,red,blue,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
   }
 }

}

       </source>
   
  

Adding Values to an Array: Assigning Values Using Array-Access Notation

   <source lang="java">

package{

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

       var aEmployees:Array = new Array(4);
       aEmployees[0] = "A";
       aEmployees[1] = "P";
       aEmployees[2] = "C";
       aEmployees[3] = "H";
       trace(aEmployees.toString());
   }
 }

}

       </source>
   
  

if you assign a value to an element that has not yet been created, actionscript creates that element, and any other elements with indices between.

   <source lang="java">

package{

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

       var aEmployees:Array = new Array(4);
       aEmployees[0] = "A";
       aEmployees[1] = "P";
       aEmployees[2] = "C";
       aEmployees[3] = "H";
       
       aEmployees[9] = "Ruth";
       
       
       trace(aEmployees.toString());  //A,P,C,H,,,,,,Ruth
   }
 }

}

       </source>
   
  

Read the data from an array using array-access notation to access one element at a time.

   <source lang="java">

package{

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

       var aEmployees:Array = ["A", "P", "C", "H"];
       trace(aEmployees[0]);  // Displays: A
       trace(aEmployees[1]);  // Displays: P
       trace(aEmployees[2]);  // Displays: C
       trace(aEmployees[3]);  // Displays: H
   }
 }

}

       </source>
   
  

Referencing Array Elements

   <source lang="java">

package{

 import flash.display.Sprite;
 
 public class Main extends Sprite{
   public function Main(){
       var trees:Array = ["b", "m", "o", "c"];
       
       var firstTree:String = trees[0];
       var favoriteTree:String = trees[2];
       
       trace(firstTree);
       trace(favoriteTree);
   }
 }

}

       </source>
   
  

Setting an Element"s Value

   <source lang="java">

package{

 import flash.display.Sprite;
 
 public class Main extends Sprite{
   public function Main(){
       var cities:Array = ["Toronto", "Montreal", "Vancouver", "Waterloo"];
       cities[0] = "London";
       cities[3] = "Hamburg";
       cities[2] = 293.3;  // Notice that the datatype change is not a problem
       
       trace(cities);
   }
 }

}

       </source>
   
  

Sum the array elements

   <source lang="java">

package{

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

       var ages:Array = [12, 4, 90];
       var totalAge:Number = ages[0] + ages[1] + ages[2];   // Sum the array
       
       
       trace(totalAge);
   }
 }

}

       </source>
   
  

To add a new element to an existing array at a specific index: assign a value to that element.

   <source lang="java">

package{

 import flash.display.Sprite;
 
 public class Main extends Sprite{
   public function Main(){
       var fruits:Array = ["apples", "oranges", "pears"];
       
       fruits[3] = "tangerines";
       
       fruits[39] = "grapes";
       
       trace(fruits); // Displays: undefined
       trace(fruits[12]); // Displays: undefined

   }
 }

} apples,oranges,pears,tangerines,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,grapes undefined

       </source>
   
  

Use variable as the array index

   <source lang="java">

package{

 import flash.display.Sprite;
 
 public class Main extends Sprite{
   public function Main(){
       var cities:Array = ["Toronto", "Montreal", "Vancouver", "Waterloo"];
       
       var i:int = 1;
       cities[i] = "Beijing";
       
       
       trace(cities); //Toronto,Beijing,Vancouver,Waterloo
       
   }
 }

}

       </source>
   
  

Use variables or complex expressions to specify an element index

   <source lang="java">

package{

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

       var trees:Array = ["b", "m", "o", "c"];
       
       var i = 3;
       var lastTree:String = trees[i];
       var randomTree:String = trees[Math.floor(Math.random(  ) * 4)];
       trace(lastTree);
       trace(randomTree);
   }
 }

}

       </source>