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hclmed0
Inspiring
April 21, 2023
Answered

Scope of vars, and scope of functions

  • April 21, 2023
  • 1 reply
  • 568 views

It seems that a var defined at the top of any frame, outside of a function, is visble to all frames. It that the case? If so, if the same variables are reassigned new values in each frame, is it better to declare them all in frame1?

 

Also, it seems that functions declared in one frame are seen as duplicate if used again in another frame. While it's fine it my application to share vars across frames, should functions all be declared as private to limit their scope to the frame in which they're located?

    This topic has been closed for replies.
    Correct answer kglad

    variables should only be declared once. they can be assigned values whenever and wherever you want.

     

    with functions it's more complicated because there are anonymous functions and there are named functions.

    1 reply

    kglad
    Community Expert
    kgladCommunity ExpertCorrect answer
    Community Expert
    April 21, 2023

    variables should only be declared once. they can be assigned values whenever and wherever you want.

     

    with functions it's more complicated because there are anonymous functions and there are named functions.

    H
    hclmed0Author
    Inspiring
    April 21, 2023

    It seems I have to give every function a unique name, even if it's to add the a listener to another instance of a single button. Is that the most efficient way to do that. What are the best practices for useing the same function on mutliple branches of an interface? For example:

    cb_1.addEventListener(Event.CHANGE,cb_1F);
    function cb_1F(e:Event):void{

    on frame2

    On frame 4 needs to change to:

    cb_1.addEventListener(Event.CHANGE,cb_2F);
    function cb_2F(e:Event):void{

     

    Is that true?

    kglad
    Community Expert
    kgladCommunity Expert
    Community Expert
    April 21, 2023

    define a function once and never again.

     

    a little background follows.

     

    anonymous function is most commonly used and looks like:

     

    function something(){

     

    }

     

    a named function is:

     

    var something = function(){

     

    }

     

    they are different in sever key ways, but to simplify things, lets just discuss anonymous functions.

     

    if you define an anonymous function on frame one hundred, you can call it on frame 1 (and every other frame on the the same timeline).  frame 100 doesn't even have to play, ever.  you can even burry an anonymous function definition on a movieclip's frame 100 and call it from the main timeline's first frame.

     

    with your combobox, example, either add the same listener to all comboboxes (if the same listener function works for them all:

     

    cb_1.addEventListener(Event.CHANGE, cbF);

    cb_2.addEventListener(Event.CHANGE, cbF);

    // etc

     

    and you can define your listeners on any frame(s) and call the same function in a different frame.

     

    function cbF(e:Event):void{
    trace(e.currentTarget.selectedItem.label);
    }

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