Multidimensional array issue

[Phil Davis]

When I want to determine whether or not an array element contains 
non-whitespace, I usually say:

     if word 1 of tDataA["item"] is empty then ... (or is NOT empty)

Just another option.

Phil Davis



On 3/8/21 5:36 PM, Bob Sneidar via use-livecode wrote:
> Are you testing for empty, or are you testing if there is a value in an array variable? If there is no key matching your array variable, LC will return an empty string. An empty string is a value.
>
> Mark is using a different method, seeing if a key of an array is itself an array. If bobtest ["value"] contains another array so that bobtest ["value"] ["anumber"] contains 1, then bobtest ["value"] is an array. If bobtest ["value"] contains 1 then it is not an array.
>
> But getting the value of bobtest ["value"] ["number"] will return empty whether or not bobtest '{value"] is an array. This is why Mark is testing for an array rather than the value.
>
> It seems a bit wonky, you might think, "Why not return an error?" But trust me, when you work with arrays, especially when it comes to datagrid data, this is the best course.
>
> Bob S
>
>
>> On Mar 8, 2021, at 16:25 , HENRY LOWE via use-livecode <use-livecode at lists.runrev.com> wrote:
>>
>> Thanks Mark. There are two possible states:
>>
>> tArray[“status”] holds a value and tArray[“status”][“text”] does not
>>
>> or
>>
>> tArray[“status”][“text”] holds a value and tArray[“status”] does not
>>
>>
>> My code is trying to do the following:
>>
>> If tArray[“status”] does not hold a value then check if tArray[“status”][“text”] holds a value
>>
>>
>> The crux is how one reliably determines that an array member (e.g. tArray[“status”]) holds a value?
>>
>> I would have assumed that if the array member does not hold a value then  - if tArray[member] is empty would always return true. However that does not appear to be the case if the array is multidimensional.
>>
>>
>> It appears that both tArray[“status”] is an array and tArray[“status”][“text”] is an array are true. Am I missing something about using this syntax?
>>
>> Thanks,
>>
>> Henry
>>
>>
>>> On Mar 8, 2021, at 3:56 PM, Mark Wieder via use-livecode <use-livecode at lists.runrev.com> wrote:
>>>
>>> On 3/8/21 3:46 PM, HENRY LOWE via use-livecode wrote:
>>>
>>>> I have often used the form 'if tArray[“key1”] is empty' to determine whether an array element hold a value but this breaks if tArray[“key1”][“key2”] holds a value.
>>> Same here. Not that I've every liked that paradigm, just that it's been that way since life crawled out of the ocean.
>>>
>>> However this should do the trick.
>>>
>>> if tArray["status"] is an array then
>>> put tArray["status"]["text"] into tStatus
>>> else
>>> put tArray["status"] into tStatus
>>> end if
>>>
>>> -- 
>>> Mark Wieder
>>> ahsoftware at gmail.com
>>>
>>> _______________________________________________
>>> use-livecode mailing list
>>> use-livecode at lists.runrev.com
>>> Please visit this url to subscribe, unsubscribe and manage your subscription preferences:
>>> http://lists.runrev.com/mailman/listinfo/use-livecode
>>
>> _______________________________________________
>> use-livecode mailing list
>> use-livecode at lists.runrev.com
>> Please visit this url to subscribe, unsubscribe and manage your subscription preferences:
>> http://lists.runrev.com/mailman/listinfo/use-livecode
> _______________________________________________
> use-livecode mailing list
> use-livecode at lists.runrev.com
> Please visit this url to subscribe, unsubscribe and manage your subscription preferences:
> http://lists.runrev.com/mailman/listinfo/use-livecode

-- 
Phil Davis
503-307-4363