Multidimensional array issue

[Bob Sneidar]

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
>> 
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