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PilotPirx

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Joined: 03/11/2020
Location: Germany
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Posted: 11:06am 10 Feb 2026

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Surrounded by the collective expertise of MMBASIC, I would like to ask a simple question:

How can I write the following query shorter?

If (monat%=1) Or (monat%=3) Or (monat%=5) Or (monat%=7) Or (monat%=8) Or (monat%=10) Or (monat%=12) Then tag% = 31
If (monat%=4) Or (monat%=6) Or (monat%=9) Or (monat%=11) Then tag% = 30
If monat% = 2 Then tag% = 28

My first try didn't work:
If monat% = 1 Or 3 Or 5 Or 7 Or 8 Or 10 Or 12 Then tag% = 31
If monat% = 4 Or 6 Or 9 Or 11 Then tag% = 30
If monat% = 2 Then tag% = 28

matherp
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Location: United Kingdom
Posts: 10934

Posted: 11:14am 10 Feb 2026

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set up an array
answer%(12)=(...)
tag%(n)=answer%(monat%)
Edited 2026-02-10 21:15 by matherp

PilotPirx

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Joined: 03/11/2020
Location: Germany
Posts: 114

Posted: 11:18am 10 Feb 2026

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Thanks, sometime i'm stupid...

Volhout
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Location: Netherlands
Posts: 5671

Posted: 11:19am 10 Feb 2026

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Alternatively use SELECT CASE
Similar to this (from the manual)

Volhout

PicomiteVGA PETSCII ROBOTS

phil99

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Location: Australia
Posts: 2991

Posted: 11:23am 10 Feb 2026

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Beaten to it by Peter.

> dim m%(12)=(0,31,28,31,30,31,30,31,31,30,31,30,31)
> for monat% = 1 to 12 : tag% = m%(monat%) : :? monat%,tag% :next
1 31
2 28
3 31
4 30
5 31
6 30
7 31
8 31
9 30
10 31
11 30
12 31
>

robert.rozee
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Location: New Zealand
Posts: 2492

Posted: 01:15pm 10 Feb 2026

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the two key lines in the below program are:

If (month<8) Xor (month And 1) Then days=30 Else days=31
If month=2 Then days=28+((year And 3)=0)-((year Mod 100)=0)

the above also checks if the year is a multiple of 4, but not a multiple of 100, in which case February has 29 days.

cheers,
rob :-)

Micromite MKII MMBasic Ver 5.05.05
Copyright 2011-2022 Geoff Graham
>
>
> LIST
Data "January ", "February ", "March ", "April "
Data "May ", "June ", "July ", "August "
Data "September", "October ", "November ", "December "

year=2026

For month=1 To 12
  If (month<8) Xor (month And 1) Then days=30 Else days=31
  If month=2 Then days=28+((year And 3)=0)-((year Mod 100)=0)
Read name$
  Print name$, month, days
Next month
End
>
>
> RUN
January 1 31
February 2 28
March 3 31
April 4 30
May 5 31
June 6 30
July 7 31
August 8 31
September 9 30
October 10 31
November 11 30
December 12 31
>
>

Edited 2026-02-10 23:18 by robert.rozee

Martin H.

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Joined: 04/06/2022
Location: Germany
Posts: 1350

Posted: 02:23pm 10 Feb 2026

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robert.rozee said the two key lines in the below program are:

If (month<8) Xor (month And 1) Then days=30 Else days=31
If month=2 Then days=28+((year And 3)=0)-((year Mod 100)=0)

the above also checks if the year is a multiple of 4, but not a multiple of 100, in which case February has 29 days.

cheers,
rob :-)

Clever

,
but ...
Physically, a year has 365.2422 days.
To compensate for this, the 400-year exception was introduced.

Quote
Every year in which the Western calendar year is divisible by 4 is a leap year.
A year in which the AD year is divisible by 100 is usually a normal year.
However,
every year is divisible by 400 is a leap year.

so to make it 100% perfect you have to add the 400-year rule.

If month=2 and Not(year Mod 400) Then days=29

that is why 2000 was a leap year

Cheers
Martin
Edited 2026-02-11 00:31 by Martin H.

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robert.rozee
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Posted: 03:18pm 10 Feb 2026

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Martin: well spotted, i'd forgotten about the 400 year rule!

it could probably be handled by:

If month=2 Then
days=28+((year And 3)=0)-((year Mod 100)=0)+((year Mod 400)=0)
EndIf

If month=2 Then
days=28+((year And 3)=0)
If (year Mod 100)=0 Then days=days-((year Mod 400)<>0)
EndIf

both look messy - can you think of a more elegant way?

cheers,
rob :-)
Edited 2026-02-11 01:20 by robert.rozee

Martin H.

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Location: Germany
Posts: 1350

Posted: 03:53pm 10 Feb 2026

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Hi Rob

robert.rozee said
both look messy - can you think of a more elegant way?

I am working with Excel since 1997. Including true and false in the calculation formulas looked similar to your example.

days=28+((year And 3)=0)-((year Mod 100)=0)+((year Mod 400)=0)

is already elegant

A more elegant solution that comes to mind could only be cosmetic in nature.

days=28+(Not (year Mod 4))-(Not(year Mod 100))+(Not(year Mod 400))

test:

cls
for year=1994 to 2010
month=2
if month=2 then
days=28+(not (year mod 4))-(Not(year Mod 100))+(Not(year mod 400))
?year,days
next

Cheers
Martin

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PilotPirx

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Joined: 03/11/2020
Location: Germany
Posts: 114

Posted: 04:04pm 10 Feb 2026

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Thanks, you've really helped me out.
With so much feedback, I'll ask another question about the new V6.02.00:

Can “object” (unquoted token) be replaced by a variable in the new STAR and ASTRO commands?
I tried using a string variable and an ARRAY element, but I always get the “Argument count” error.
How do I convert a string into a token?

Program excerpt:

OPTION BASE 1
Dim solar$(9)=("SUN","MOON","MERCURY","VENUS","MARS","JUPITER","SATURN","URANUS","NEPTUNE")
Dim x%

for x%=1 to 9
Astro solar$(x%), alt,az
print alt,az
next x%

phil99

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Joined: 11/02/2018
Location: Australia
Posts: 2991

Posted: 08:34pm 10 Feb 2026

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Have encountered a similar error in other situations where a function wont accept a parameter that needs to be evaluated.
The solution was an intermediate variable.

See if this works. Untested:-

OPTION BASE 1
Dim solar$(9)=("SUN","MOON","MERCURY","VENUS","MARS","JUPITER","SATURN","URANUS","NEPTUNE")
Dim x%, Planet%

for x%=1 to 9
Planet% = solar$(x%)
Astro Planet%, alt,az
print alt,az
next x%

Edited 2026-02-11 06:35 by phil99

Footnote added 2026-02-11 06:43 by phil99
JohnS (below) may be right. the coma may be the issue.
The intermediate variable may avoid the need to "Execute" the command.

OPTION BASE 1
Dim solar$(9)=("SUN","MOON","MERCURY","VENUS","MARS","JUPITER","SATURN","URANUS","NEPTUNE")
Dim x%, Planet%

for x%=1 to 9
Planet% = solar$(x%)
Astro Planet% alt,az
print alt,az
next x%

JohnS
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Joined: 18/11/2011
Location: United Kingdom
Posts: 4226

Posted: 08:35pm 10 Feb 2026

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I think you may need to remove the comma after object and also use such as EXECUTE

The syntax will be a bit painful...

John

Volhout
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Posted: 08:55pm 10 Feb 2026

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How do you change a string into an integer ?

Planet% = solar$(x%)

Volhout

PicomiteVGA PETSCII ROBOTS

phil99

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Location: Australia
Posts: 2991

Posted: 09:06pm 10 Feb 2026

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Too early, not thinking yet.

OPTION BASE 1
Dim solar$(9)=("SUN","MOON","MERCURY","VENUS","MARS","JUPITER","SATURN","URANUS","NEPTUNE")
Dim x%, Planet$

for x%=1 to 9
Planet$ = solar$(x%)
Astro Planet$ alt,az
print alt,az
next x%

Edited 2026-02-11 07:10 by phil99

JohnS
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Posts: 4226

Posted: 09:17pm 10 Feb 2026

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I didn't notice the % on Planet%, yes would need to be Planet$

The manual says the object needs to be a literal (my term), i.e. without quotes, so Planet$ is unlikely to work, which is why I think EXECUTE will be needed.

John

phil99

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Posts: 2991

Posted: 10:04pm 10 Feb 2026

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Even EXECUTE doesn't work.

> LIST
Option BASE 1
Dim x%, Planet$
Dim solar$(9)=("SUN","MOON","MERCURY","VENUS","MARS","JUPITER","SATURN","URANUS","NEPTUNE")
Location "25/12/2025 22:30:00", -33.86, 151.21

For x%=1 To 9
Planet$ = solar$(x%)
Execute "Astro Planet$ alt,az"
Print alt,az
Next x%
End

> RUN
[9] Execute "Astro Planet$ alt,az"
Error : Argument count
>

Edit.
The word "Execute" isn't the problem.
You simply have to repeat the whole "Astro" command for each object.

> Location "25/12/2025 22:30:00", -33.86, 151.21
> Execute "Astro mars alt,az"
> ? alt,az"
41.38080261 93.62855765
>
>
> Location "25/12/2025 22:30:00", -33.86, 151.21
> M$= "Mars"
> Execute "Astro M$ alt,az"
Error : Argument count
>

Edit 2
It works if the whole line is in the string variable.

> Location "25/12/2025 22:30:00", -37, 145
> M$= "Mars"
> P$ = "Astro "+M$+" alt,az"
> Execute P$
> ? alt,az
36.55387517 94.41380944
>

Edited 2026-02-11 08:27 by phil99

lizby
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Location: United States
Posts: 3605

Posted: 10:22pm 10 Feb 2026

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This doesn't error:

Quote > Location "25/12/2025 22:30:00", -33.86, 151.21
> M$= "Mars"
> Execute "Astro "+M$+" alt,az"
>

(though I don't know what it does).

PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed

phil99

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Location: Australia
Posts: 2991

Posted: 10:33pm 10 Feb 2026

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I am really not thinking clearly today. Forgot to assemble the string properly.

Quote (though I don't know what it does).

You just need to "Print alt, az" to see.

> LIST
Option BASE 1
Dim x%
Dim solar$(9)=("SUN","MOON","MERCURY","VENUS","MARS","JUPITER","SATURN","URANUS","NEPTUNE")
Location "25/12/2025 22:30:00", -33.86, 151.21

For x%=1 To 9
Execute "Astro "+solar$(x%)+" alt,az"
Print alt,az
Next x%
End

> RUN
44.1771112 90.81148523
-20.55688641 113.5411261
57.3981952 79.62275258
46.98224175 89.46095847
41.38080261 93.62855765
-28.45141629 278.548886
-30.20043832 120.2273839
-71.65809912 222.6414771
-35.36963401 121.4384382
>

JohnS had the answers all along.
Edited 2026-02-11 08:58 by phil99

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