How to manage Arrays as Object members

Question

I found a realy strange behavior with the instanciation of a
Class which contains an Array member.
Here is the code wich is self explanatory.

Answer 1

Create the array instance in the constructor.
class MyObj {
public var tab:Array;
function MyObj(index) {
this.tab= new Array();
"Chris_007" <[email protected]> wrote in
message
news:[email protected]...
> I found a realy strange behavior with the instanciation
of a Class which
> contains an Array member.
>
> Here is the code wich is self explanatory.
>
>
>
>
>
> class MyObj {
> //
> public var tab:Array = new Array();
> private var objectName:String;
> private var theIndex:Number;
> //
> // Constructeur
> function MyObj(index) {
> this.theIndex = index;
> // Object name
> this.objectName = "name#" + index;
> for (var i = 0; i < 3; i++) {
> this.tab
= index * 3 + i;
> }
> }
> //
> function printObject() {
> trace(" Printing Object name --> " +
this.objectName);
> for (var i = 0; i < 3; i++) {
> trace(" tab[" + i + "] : " + this.tab);
> }
> }
> //
> function getClone() {
> return new MyObj(theIndex);
> }
> }
>
>
> // And the main scenario code
> //
> var index:Number = 0;
> //
> var objArray:Array = new Array();
> //
> var oob:MyObj;
> //
> function printMyArray(arr:Array):Void {
> for (var i = 0; i < arr.length; i++) {
> trace(" tab[" + i + "] : " + arr
> }
> }
> //
> // Filling in the Array
> for (var i = 0; i < 4; i++) {
> oob = new MyObj(index);
> // oobj = oob.getClone();
> trace("-- New object #" + i + " created. MyObj[" + index
+ "]");
> oob.printObject();
> objArray = oob;
> trace("-- Now entered into the array -- printing from
object #" + i );
> objArray
.printObject();
> trace("-- or printing from the scenario -- objArray[" +
i + "] is realy
> stored");
> printMyArray(objArray.tab);
> trace("____________________________________");
> index += 1;
> }
> //
> // Printing the array of pointers to MyObj
> trace("___________________________________________");
> trace("And now, all in one...\nPrinting the array of
pointers to MyObj
> trace("___________________________________________");
> for (var i = 0; i < 4; i++) {
> objArray
.printObject();
> }
> trace("------ Or directly from the scenario -------");
> for (var i = 0; i < 4; i++) {
> trace(" Printing from scenario Object name --> " +
objArray.objectName);
> printMyArray(objArray
.tab);
> }
> trace("___________________________________________");
> trace("They are all the same ?!\nIt seems to have lost
something !!!!");
> trace("___________________________________________");
> //
> //
> trace("\nAmazingly, the array's elements do not refer to
the same
object\n");
> //
> trace("objArray[0] == objArray[0] ? -->" +
(objArray[0] == objArray[0]));
> trace("objArray[0] == objArray[1] ? -->" +
(objArray[0] == objArray[1]));
> trace("objArray[0] instanceof MyObj ? -->" +
(objArray[0] instanceof
MyObj));
> trace("");
> //
> trace("\nThey realy seem to point different objects
!\n");
> //
> // So, why do they have different outputs ?
> //
> //
> //
> // It seems the 'new' constructor creates a new Object
'MyObj'
> // which always resides at the same memory location.
> // 'oob' is in fact a pointer, and objArray[] an array
of pointers,
> // as so an array of memory addresses.
> // The objArray[] elements are pointers which always
refer to the
> // the same memory zone, which in fact contains the last
content of the
> object.
> //
> //
> // And then manualy
> //
>
trace("**********************************************************");
> trace("\nAnd then another way to create each new object
manualy\n");
>
trace("**********************************************************");
> //
> //
> var otherObjArray:Array = new Array();
> //
> var oob0 = new MyObj(100);
> trace("-- New object created #100");
> oob0.printObject();
> otherObjArray[0] = oob0;
> trace("-- Now entered into the array --
otherObjArray[0]");
> otherObjArray[0].printObject();
> //
> var oob1 = new MyObj(200);
> trace("-- New object created #200");
> oob1.printObject();
> otherObjArray[1] = oob1;
> trace("-- Now entered into the array --
otherObjArray[1]");
> otherObjArray[1].printObject();
> //
> var oob2 = new MyObj(300);
> trace("-- New object created #300");
> oob2.printObject();
> otherObjArray[2] = oob2;
> trace("-- Now entered into the array --
otherObjArray[2]");
> otherObjArray[2].printObject();
> //
> trace("___________________________________________");
> trace("And now, all in one...\nEnjoy the show !!!!");
> trace("___________________________________________");
> otherObjArray[0].printObject();
> otherObjArray[1].printObject();
> otherObjArray[2].printObject();
> //
> trace("\nThe problem seems to reside in the way the
Arrays members are
managed
> by the Objects !\n");
> trace("\nHELP me please to find the bug\n");
> //
>