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Array: 0 and empty values
Posted: Sat May 11, 2019 10:14 am
by Zax
Hello,
Maybe it has been already discussed but I don't understand why 0 numeric values are modified to empty values in arrays.
Example:
Code: Select all
put "Peter" into arr1["name"]
put 0 into arr1["level"]
answer arr1["name"] & cr & arr1["level"]
--> OK
put arr1 into arr2
answer arr2["name"] & cr & arr2["level"]
--> display "Peter" and an empty line !!!
Any idea?
Re: Array: 0 and empty values
Posted: Sat May 11, 2019 10:36 am
by richmond62
I fail to see any great difference between 0 and 'empty'; equating, as they do, to the same thing.
If 'empty' offends you then I suppose you could do something like this:
Code: Select all
put arr1 into arr2
put arr2["level"] into LLEVEL
if LLEVEL is empty then put 0 into LLEVEL
answer arr2["name"] & cr & LLEVEL
Re: Array: 0 and empty values
Posted: Sat May 11, 2019 10:41 am
by LCMark
@zax: They aren't - if you put 0 into an array element, it stays as 0.
Indeed, I tried:
Code: Select all
put "Peter" into arr1["name"]
put 0 into arr1["level"]
answer arr1["name"] & cr & arr1["level"]
put arr1 into arr2
answer arr2["name"] & cr & arr2["level"]
In the message box in 9.0.x and it displayed the same thing both times.
Re: Array: 0 and empty values
Posted: Sat May 11, 2019 11:26 am
by bogs
I am also curious why your seeing a different result than what you would expect. Being the lazy cuss I am, I copied your code directly from the posting to a message box, both answer dialogs came back exactly the same in 6.x to 8.x versions on 'nix.
- Answer 1...
- Answer 2...
Which OS and version are you finding something different in?
Re: Array: 0 and empty values
Posted: Sat May 11, 2019 12:01 pm
by Zax
Ahem, I'm very embarrassed because now I've got a correct answer with 0 value
However, I did not dream. I 'll try to pay attention to my script, to see It will happen again.
Anyhow, thanks for you replies.
@
richmond62
Empty is... an empty string, and 0 is an integer
I know in PHP for example, false value and empty are the same, but testing I think a 0 numeric value should not be the same as an empty value.
Re: Array: 0 and empty values
Posted: Sat May 11, 2019 1:08 pm
by richmond62
With LC 9.0.3 and MacOS 10.14.5 I didn't get an answer window!
-
Re: Array: 0 and empty values
Posted: Sat May 11, 2019 1:28 pm
by Klaus
Well, I get the answer dialog as advertized:
Peter
0
Answer1
Via message box and via a button:
Code: Select all
on mouseUp pMouseButton
put "Peter" into arr1["name"]
put 0 into arr1["level"]
answer arr1["name"] & cr & arr1["level"] & CR & "Answer1"
end mouseUp
macOS 10.14.4 (10.14.5 is yet to come
) and LC 9.03.
Re: Array: 0 and empty values
Posted: Sat May 11, 2019 2:20 pm
by richmond62
macOS 10.14.4 (10.14.5 is yet to come
) and LC 9.03.
-
- Screenshot 2019-05-11 at 16.18.56.png (38.65 KiB) Viewed 7960 times
-
Re: Array: 0 and empty values
Posted: Sat May 11, 2019 2:27 pm
by Klaus
Ah, the Bertha version, OK, I would never trust the results of testing on a beta OS sytem.
Re: Array: 0 and empty values
Posted: Sat May 11, 2019 3:03 pm
by [-hh]
zax wrote:Empty is... an empty string, and 0 is an integer
In LC everything is a string.
There are situations where empty is evaluated as zero.
For example 1*empty yields zero and 1+empty yields one.
Also empty parameters of a handler/function are handled as zero:
Code: Select all
function testIt x
return x is zero
end testIt
Then testIt() returns true.
Nothing strange, but good to know.
Re: Array: 0 and empty values
Posted: Sat May 11, 2019 3:10 pm
by bogs
[-hh] wrote: Sat May 11, 2019 3:03 pm
Nothing strange, but good to know.
Very good to know, I had assumed it was as zax wrote.
Re: Array: 0 and empty values
Posted: Sat May 11, 2019 4:48 pm
by Zax
[-hh] wrote: Sat May 11, 2019 3:03 pm
Nothing strange, but good to know.
Interesting!
(I hate these internal type conversions/transformations, but I suppose that's the price to have an easy programming langage)