Usage of MID()

[matalog]

If I set up a string STR1:="123";

Then I use MID(STR1,9), it will return the last digit "3", even though it is the 3rd position of the string, I would thought it would have returned "" given that there is nothing in the 9th position.

Using PUREBASIC for example, I get nothing output to terminal.

MID("123",6) on the Prime, returns 3.

Is that normal?

[toml_12953]

(04-15-2022 09:41 PM)matalog Wrote:  If I set up a string STR1:="123";

Then I use MID(STR1,9), it will return the last digit "3", even though it is the 3rd position of the string, I would thought it would have returned "" given that there is nothing in the 9th position.

Using PUREBASIC for example, I get nothing output to terminal.

MID("123",6) on the Prime, returns 3.

Is that normal?

I don't like it but that's the way it works on mine, too.

[matalog]

It doesn't work like that on the 50g, SUB(4,4,"123") doesn't return anything.

Casio CG50 StrMid("123",5,5) doesn't return anything.

I don't know of another language where MID will return something outside of the set range.

[Albert Chan]

(04-15-2022 09:41 PM)matalog Wrote:  MID("123",6) on the Prime, returns 3.

With lower-cased mid, bug is gone (at least on the emulator)

CAS> mid("123",6)      → ""

[matalog]

(04-16-2022 01:56 PM)Albert Chan Wrote:  

(04-15-2022 09:41 PM)matalog Wrote:  MID("123",6) on the Prime, returns 3.

With lower-cased mid, bug is gone (at least on the emulator)

CAS> mid("123",6)      → ""

And confirmed on a G2.

Is there any way to ensure the CAS version of MID will be used from any program?

That should be enough to all it a bug. There is no reason to have MID behave differently in CAS than Home.

[StephenG1CMZ]

This will work in PPL:
ST:="123";
CAS("mid(ST, 6) ");
It also works from CAS home screen - I haven't tried it within a CAS program.

[matalog]

(04-16-2022 05:06 PM)StephenG1CMZ Wrote:  This will work in PPL:
ST:="123";
CAS("mid(ST, 6) ");
It also works from CAS home screen - I haven't tried it within a CAS program.

That is the second time this week I have seen a suggestion to use CAS( something) as a work around.

What does that use of CAS do, as it usually contains more quotations that you would usually see?

Is it documented in the manual?

[StephenG1CMZ]

The short answer:
The expression is parsed by CAS and more information is available in CAS help.
I have seen CAS(string) used, and also CAS.function (e.g. CAS.mid(...) ).
It's an alternative to just using mid within a CAS program.
Note that MID is normally the PPL version and mid the CAS version, though their are exceptions.

I am sure the experts can explain it much better.

[jte]

matalog,

Thanks for posting. And thanks to the others for their comments and confirmation. I filed a bug report for this on the bug tracking site I’ve set up. … and the bug got fixed!

(If anyone reading this would like an account on the bug tracker I’ve set up to help organize matters, just let me know by PM.)

[jte]

Unfortunately, the fix has broken at least one program; see https://www.hpmuseum.org/forum/thread-11...#pid168494. Luckly, there, a quick patch to the game’s source code (for loading “sayings”) seems to do the trick. (E.g., changing “DIM(str)==1” to “DIM(str)<2”.)