Subs parameters

[merli]

Hello

I would like to have some way to return from Sub more then one value.
For example:

Sub min_max(a,b,min,max)
If a<b Then
min=a
max=b
Else
min=b
max=a
End If
End Sub

Calling as:
min_max(no1,no2,minimum,maximum)

I would expect after run filled out variables minimum and maximum with right values.

Thnx

[derez]

Your wish can be answered in two options :
1. to define min and max as global, then they are changed by the sub and you can refer to their value outside of the sub (and they should not be in the arguments list).
2. to return one variable which is a string : min & "," & max, and then use an array of 2 to split it

Dim mix(2)

sub min_max(a,b)
...
...
return min & "," & max
end sub

mix() = strsplit(min_max(a,b) , ",")
min = mix(0)
max = mix(1)

[klaus]

I agree with merli.
I had this wish to pass parameters to subroutines also by reference and not only by value, some time ago.

Erel's answer:

It will be supported in a future version too (not sure when though).

here : http://www.basic4ppc.com/forum/quest...n-1-value.html

Unfortunately it was not in the wishlist, but in a 'Question & Help needed' thread.

Best regards.

[Erel]

Passing variables by reference will be supported in the next version (its release date is not set yet).

[klaus]

That sounds like good news.

Thank you Erel.

Best regards.

[merli]

Originally Posted by derez

Your wish can be answered in two options :
1. to define min and max as global, then they are changed by the sub and you can refer to their value outside of the sub (and they should not be in the arguments list).
2. to return one variable which is a string : min & "," & max, and then use an array of 2 to split it

Dim mix(2)

sub min_max(a,b)
...
...
return min & "," & max
end sub

mix() = strsplit(min_max(a,b) , ",")
min = mix(0)
max = mix(1)

Nice workaround, but you still have to have arrays global declared. Erel, is it planned to have posibility declare arrays localy?

[mjcoon]

Originally Posted by merli

Nice workaround, but you still have to have arrays global declared. Erel, is it planned to have posibility declare arrays locally?

How would that work, except by having arrays (or other variables) passed by reference so that the names are local to the Sub but the data that is manipulated is external to the Sub? (Which is what we are promised for a future version.)

Using globals is so clunky because to operate on varied data each has to be loaded into the global(s) before calling the Sub and then "unloaded" afterwards. This doesn't help with the readability of the code.

Mike.

[Erel]

Nice workaround, but you still have to have arrays global declared. Erel, is it planned to have posibility declare arrays localy?

Declaring local arrays and structures was initially planned for the next version. Though I believe it will only be added in the following version.

[merli]

Originally Posted by mjcoon

How would that work, except by having arrays (or other variables) passed by reference so that the names are local to the Sub but the data that is manipulated is external to the Sub? (Which is what we are promised for a future version.)

Using globals is so clunky because to operate on varied data each has to be loaded into the global(s) before calling the Sub and then "unloaded" afterwards. This doesn't help with the readability of the code.

Mike.

You are right, but there is another problem when I want to use in Sub some helping temporary array which won't be used after return. I still have to now define this array Global

[mjcoon]

Originally Posted by merli

... when I want to use in Sub some helping temporary array which won't be used after return. I still have to now define this array Global

Yes, the relaxed implicit-variant treatment of local variables does not work for arrays. This is because all elements of the array have to have the same variant for the indexing mechanism to work (I suppose), so the easy way out is to require all arrays to be declared in a "Dim" before they are used.

Erel has mentioned making variables more sophisticated in the past, so perhaps including a local "Dim" could be introduced for local arrays.

Mike.