[Javascript] Object Not Defined

[Terry Riegel]

Exactly, do you have the code for isDeclared?

Terry

Sent from my iPhone

On Nov 20, 2011, at 2:30 PM, Troy III Ajnej <trojani2000 at hotmail.com> wrote:

>
> I see what you mean...
>
>
>
> I think you'll need my >>isDeclared()<< method I've written sometime
>
> ago for testing variable existence, that is: discern if a variable is
>
> declared or undeclared in order to safely delete it as soon as I'm
>
> done working with it, or programmaticaly declare a new one.
>
>
>
> There's no need for:
>
>> if( a && a.b && a.b.c && a.b.c.d && a.b.c.d.e && a.b.c.d.e.f&&
>
>> a.b.c.d.e.f.title ) { return ....
>
> in case you are interested in directly obtaining a title value, you'll
>
> go strait at: "a.b.c.d.e.f.title".
>
> I think,
> you would like something like:
> ---------------------------------------------------------------------
> function getDSOvalue( dsoVal, default ){ return isDeclared(dsoVal) ? dsoVal : default }
> getDSOvalue( "a.b.c.d.e.f.title", "untitled" );
>
> ---------------------------------------------------------------------
>
>
>
> is this correct?
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Troy III
> progressive art enterprise
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>
>
>> From: riegel at clearimageonline.com
>> Date: Sun, 20 Nov 2011 13:08:30 -0500
>> To: javascript at lists.evolt.org
>> Subject: Re: [Javascript] Object Not Defined
>>
>> The point is I would like to test for the *existence* of an object of some
>> arbitrary level a.b.c.d.e.f.title and not have a mess of code to do so.
>> Currently the code would look like this.
>>
>> if( a && a.b && a.b.c && a.b.c.d && a.b.c.d.e && a.b.c.d.e.f &&
>> a.b.c.d.e.f.title ) { return a.b.c.d.e.f.title } else { return 'untitled' }
>>
>> What I would prefer is more readable code like this...
>>
>> if( exist(a.b.c.d.e.f.title) ) {return a.b.c.d.e.f.title} else {return
>> 'untitled'}
>>
>> Unfortunately the second form makes sense but isn't valid. Is there a way
>> to make a function exist() that would make it valid?
>>
>> Terry
>>
>>
>>
>> On Nov 19, 2011, at 9:58 PM, Troy III Ajnej <trojani2000 at hotmail.com> wrote:
>>
>>
>> Hi one thing I don't understand is why are you returning an (object by
>> default) instead of (one would expect) a boolean, -logically a false
>> one!But that's probably because of your sepcific algo requirements there.
>> For this part of an a conditional:> if(a && a.data && a.data.items){ I
>> presume that this :if (typeof a!='undefined'){return a.data||[]...
>> would do just fine. You can however write a ternary assignment if you
>> like: var zeeData = (typeof a!='undefined') ? a.data.items||a.data:[] or
>> you can also have a function + arguments working their ass for you:
>> function(a, data, item ){ return( typeof a != 'undefined' ) ?
>> a[data][item] || a[data] || [] : [];}
>> !This will retrieve an altrenative, in case a.data.item is not presentyou
>> will recieve the "a.data" content instead of empty [] if it exists, or if
>> that's not of any (I presume) practical use for you, -you can: function(a,
>> data, item ){ return( typeof a != 'undefined' ) ? a[data] ?
>> a[data][item] : [] : [];}
>> Or perhaps: function zeeData(a, data, items ){
>> return( typeof a & a[data] != 'undefined' ) ? a[data][items] || [] : [ ];
>> }
>> since if I understood it well - you are targeting the third row,this would
>> be a better choice, or my final thought on this turn I guess.
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> Troy III
>> progressive art enterprise
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> From: riegel at clearimageonline.com
>>
>> Date: Fri, 11 Nov 2011 07:45:07 -0500
>>
>> To: javascript at lists.evolt.org
>>
>> Subject: [Javascript] Object Not Defined
>>
>>
>> Hello All,
>>
>>
>> I am looking for a better way for the following piece of code...
>>
>>
>> function(a){
>>
>> if(a && a.data && a.data.items){
>>
>> return a.data.items;}
>>
>> else{
>>
>> return[];
>>
>> }
>>
>> }
>>
>>
>> It would be nice if this did the same thing...
>>
>>
>> function(a){return a.data.items || []};
>>
>>
>> Anyone have any thought on how this could be done I wouldn't mind wrapping
>> it into a function if that helped. Something like this possibly...
>>
>>
>>
>> function(a){return or(a.data.items,[]) };
>>
>>
>>
>> Thanks for any help.
>>
>>
>> Terry
>>
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