[Xerte] Loop through an object?

[Paul Swanson]

Use the for..in statement:

 

for..in Statement

 

Usage

                

 

for (variableIterant in object) {

    statement(s); 

} 

 

Player version: Flash Player 5

 

Iterates over the properties of an object or elements in an array and
executes the statement for each property or element. Methods of an
object are not enumerated by the for..in action.

 

Some properties cannot be enumerated by the for..in action. For example,
movie clip properties, such as _x and _y, are not enumerated. In
external class files, static members are not enumerable, unlike instance
members.

 

The for..in statement iterates over properties of objects in the
iterated object's prototype chain. Properties of the object are
enumerated first, then properties of its immediate prototype, then
properties of the prototype's prototype, and so on. The for..in
statement does not enumerate the same property name twice. If the object
child has prototype parent and both contain the property prop, the
for..in statement called on child enumerates prop from child but ignores
the one in parent.

 

The curly braces ({}) that are used to enclose the block of statements
to be executed by the for..in statement are not necessary if only one
statement is executed.

 

If you write a for..in loop in a class file (an external AS file), then
instance members are not available for the loop, but static members are.
However, if you write a for..in loop in a FLA file for an instance of
the class, then instance members are available but static ones are not.

 

Parameters

                variableIterant:String - The name of a variable to act
as the iterant, referencing each property of an object or element in an
array.

 

Example

 

The following example uses for..in to iterate over the properties of an
object:

 

var myObject:Object = {firstName:"Tara", age:27, city:"San Francisco"}; 

for (var prop in myObject) { 

    trace("myObject."+prop+" = "+myObject[prop]); 

} 

//output 

myObject.firstName = Tara 

myObject.age = 27 

myObject.city = San Francisco

 

The following example uses for..in to iterate over the elements of an
array:

 

var myArray:Array = new Array("one", "two", "three"); 

for (var index in myArray) 

    trace("myArray["+index+"] = " + myArray[index]); 

// output: 

myArray[2] = three 

myArray[1] = two 

myArray[0] = one

 

The following example uses the typeof operator with for..in to iterate
over a particular type of child:

 

for (var name in this) { 

    if (typeof (this[name]) == "movieclip") { 

        trace("I have a movie clip child named "+name); 

    } 

}

 

Note: If you have several movie clips, the output consists of the
instance names of those clips.

 

The following example enumerates the children of a movie clip and sends
each to Frame 2 in its respective Timeline. The RadioButtonGroup movie
clip is a parent with three children: _RedRadioButton_,
_GreenRadioButton_,, and _BlueRadioButton_.

 

for (var name in RadioButtonGroup) {
RadioButtonGroup[name].gotoAndStop(2); }

 

From: xerte-bounces at lists.nottingham.ac.uk
[mailto:xerte-bounces at lists.nottingham.ac.uk] On Behalf Of Dave Burnett
Sent: Wednesday, October 13, 2010 3:35 PM
To: Xerte list
Subject: [Xerte] Loop through an object?

 


myobject = new Object();


myobject[130] = "alpha";
myobject[230] = "bravo";
myobject[330] = "charlie";

Not knowing the numerics that will wind up in there, how do I loop
through it?

e.g. I want to match the alpha values to something else and get the
property.









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