Flash / Flex / ActionScript/Array/splice

Extracting Subsets of Array Elements

 
package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        var aEmployeesAll:Array = ["A", "P", "C", "H",
                                   "Gilberto", "Mary", "Ayla", "Riad"];
        var aEmployeesExec:Array = aEmployeesAll.slice(0, 4);
        var aEmployeesNew:Array = aEmployeesAll.slice(4, 6);
        var aEmployeesStaff:Array = aEmployeesAll.slice(6);
        trace(aEmployeesExe.toString());
        trace(aEmployeesNew.toString());
        trace(aEmployeesStaff.toString());
    }
  }
}
A,P,C,H
G,M
A,R

Inserting Elements into an Array: arrayName.splice(startingIndex, numberOfElementsToDelete, element1[,...elementN]);

 

package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        var aEmployees:Array = ["A", "P", "C", "H"];
        aEmployees.splice(3, 0, "R", "H", "L");
        trace(aEmployees.toString()); // A,P,C,R,H,L,H
    }
  }
}

Removing Elements from Within an Array

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

        var aEmployees:Array = ["A", "P", "C", "H"];
        var aRemovedEmployees:Array = aEmployees.splice(2, 2);
        trace(aEmployees.toString());
        trace(aRemovedEmployees.toString());
    }
  }
}
//A,P
//C,H

splice( ) can both remove elements from and add elements to an array.

 

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

        var letters:Array = ["a", "b", "c", "d", "e", "f"];
        letters.splice(1, 3);
        letters.splice(1);
        
        trace(letters); // a
    }
  }
}

splice( ) returns a new array containing the deleted elements

 
package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        var letters:Array = ["a", "b", "c", "d"];
             
        var deleted:Array = letters.splice(0, 2);
             
        for (var i:int = 0; i < deleted.length; i++) {
            trace(deleted[i]);
        }
    }
  }
}

The splice( ) method can add elements to, or remove elements from, an array.

 
theArray.splice(startIndex, deleteCount, item1, item2,...itemn)

package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        var months:Array = new Array("January", "Friday",
                                     "April", "May", "Sunday", "Monday", "July");
        months.splice(1,1);
        months.splice(1, 0, "February", "March");
        months.splice(5, 2, "June");
        months.splice(3); // months is now: ["January", "February", "March"]
                         
        trace(months); //January,February,March
    }
  }
}

Use slice( ) instead of concat( ) to create a copy of an array

 
package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        var letters:Array = ["a", "b", "c"];
        
        var newLetters:Array = letters.slice(0);
        
        trace(letters);        // Displays: "a,b,c"
        trace(newLetters);     // Displays: "a,b,c"
        
        letters = ["d", "e", "f"];
             
        trace(letters);        // Displays: "d,e,f"
        trace(newLetters);     // Displays: "a,b,c"
    }
  }
}
a,b,c
a,b,c
d,e,f
a,b,c

When you remove elements from an array in a for statement, you need to change the value of the index variable accordingly

 
package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        var numbers:Array = new Array(4, 10);
        numbers[4] = 1;
        trace(numbers);  // Displays: 4,10,undefined,undefined,1
        
        for(var i:int = 0; i < numbers.length; i++) {
            if(numbers[i] == undefined) {
                numbers.splice(i, 1);
            }
        }
        trace(numbers);  // Displays: 4,10,undefined,1
    }
  }
}
// 4,10,,,1
// 4,10,,1