MACROMEDIA FLEX-FLEX ACTIONSCRIPT LANGUAGE, Справочник

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Using condition statements 39
Array access operator.
You can use the array access operator to dynamically set and retrieve
instance names and variables. For example, in the following code, the expression inside the array
access operator is evaluated, and the result of the evaluation is used as the name of the variable to
be retrieved from movie clip
name
:
name["mc" + i]
In ActionScript 2.0, you can use the bracket operator to access dynamically created properties, if
the dynamic keyword was not used to define the class, as shown in the following example:
class Foo {
}
// in a fla that uses Foo
var bar:Foo = new Foo();
function barGetProp():String {
return "bar";
}
function barSetProp(str:String):Void {
}
bar.addProperty("someProp", barGetProp, barSetProp);
//trace(bar.someProp); // generates an error
trace(bar["someProp"]); // no error
You can use the
eval()
function to dynamically set and retrieve instance names and variables, as
shown in the following example:
eval("mc" + i)
The array access operator can also be used on the left side of an assignment statement. This lets
you dynamically set instance, variable, and object names, as shown in the following example:
name[index] = "Gary";
You create multidimensional arrays in ActionScript by constructing an array, the elements of
which are also arrays. To access elements of a multidimensional array, you can nest the array access
operator with itself, as shown in the following example:
var chessboard:Array = new Array();
for (var i=0; i<8; i++) {
chessboard.push(new Array(8));
}
function getContentsOfSquare(row, column){
chessboard[row][column];
}
When you use the array access operator, the ActionScript compiler cannot check if the accessed
element is a valid property of the object.
Using condition statements
To perform an action depending on whether a condition exists, or to repeat an action (create loop
statements), you can use
if
,
else
,
else if
,
for
,
while
,
do while
,
for..in
, or
switch
statements.