On 3/15/2015 11:50 AM, Graham Samuel wrote:
Still struggling with arrays: no results, no error messages,  no data… will get 
there no doubt. While trying to get there, I tried

   put exists(myArray[“gpx”])

I got ‘false’, but the IDE seems to say that the top key in this 
multidimensional array is “gpx”, so why isn’t it true?

"Exists" is only for card controls. Array elements are variables, so myArray(["gpx"]) resolves to the content of whatever is stored inside the gpx variable.

If you want to know whether there's a key named "gpx" then:

  put "gpx" is among the lines of the keys of myArray

If you want to know the content of the key named "gpx":

  put myArray["gpx"]

Devin had a cool way to explain arrays in one of our classes some years ago. He just held up an egg carton. That's an array. Each egg depression holds some kind of egg (a variable.) The egg carton can be big enough that each egg depression holds a whole different egg carton.

carton[1] = the egg in the first slot
carton[1][3] = the egg in the third slot of the carton that's in slot 1 of the main carton

The slots can be named instead of numbered. The names identify the slots, not the contents:

carton["gooseEggs"] = the value of whatever is in the slot named "gooseEggs" in the main carton

carton["gooseEggs"]["Canadian"] = the value in the slot named "Canadian" of the carton that's named "gooseEggs" which is inside the main carton

And yeah, it gets confusing when the arrays get big.

--
Jacqueline Landman Gay         |     [email protected]
HyperActive Software           |     http://www.hyperactivesw.com


_______________________________________________
use-livecode mailing list
[email protected]
Please visit this url to subscribe, unsubscribe and manage your subscription 
preferences:
http://lists.runrev.com/mailman/listinfo/use-livecode

Reply via email to