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Forum Index : Microcontroller and PC projects : MMBasic question, array assignment
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| abraxas Regular Member  Joined: 16/06/2020 Location: CanadaPosts: 99 |
Is it possible to assign an array to another variable so you can have a level of indirection? For example I’m trying to do a swap of arrays but it doesn’t work or I’m getting the syntax wrong: DIM foo(10) AS INTEGER DIM bar(10) AS INTEGER DIM baz() = foo() Above won’t work no matter what combinations of brackets or no brackets I’m trying to use. Likewise I haven’t been able to return an array from a function. I tried to do that as a substitute for swapping them via references. |
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twofingers Guru  Joined: 02/06/2014 Location: GermanyPosts: 1593 |
No. You have to copy each array element individually. Michael Edited 2020-07-16 08:36 by twofingers causality ≠correlation ≠coincidence |
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| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3378 |
Can you explain further what you mean by "a level of indirection"? I assume you don't mean: for i = 1 to 10: bar(i)=foo(i): next i Or: for i = 1 to 10: j=bar(i): bar(i)=foo(i): foo(i)=j: next i While you can't return an array in a function, you can manipulate global arrays in a sub, and I believe can manipulate arrays passed (by reference) to a sub. PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
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| abraxas Regular Member Joined: 16/06/2020 Location: CanadaPosts: 99 |
Well, that was succinct... how about the second part of my question, the part about returning arrays from functions? |
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| abraxas Regular Member Joined: 16/06/2020 Location: CanadaPosts: 99 |
No, it’s not what I’m after. I want to have a reference that refers to a different array at different times. |
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vegipete Guru Joined: 29/01/2013 Location: CanadaPosts: 1132 |
Perhaps you can use an array of arrays. Then your reference is just the index of the desired array. dim foobar(2,100) put foo(N) into foobar(1,N) put bar(N) into foobar(2,N) Use 1 to access foo, 2 to access bar. Visit Vegipete's *Mite Library for cool programs. |
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| abraxas Regular Member Joined: 16/06/2020 Location: CanadaPosts: 99 |
Great idea, that’s probably how I’m going to solve it. |
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panky Guru Joined: 02/10/2012 Location: AustraliaPosts: 1114 |
@abraxas, Not sure if this will help but the EVAL command may be a way to achieve what you want? a=0 ' array index c="x$" ' array name e$=str$(a) ' array index as string dim x$(2) ' 3 element string array x$(0)="hi" ' array first slot x$(1)="lo" ' array second slot ' do something with the array print eval(c$+"("+e$+")") ' use EVAL to plug in variable names So, by changing just a and c$ you could reference any element of any array. (tested on a CMM2 panky ... almost all of the Maximites, the MicromMites, the MM Extremes, the ArmMites, the PicoMite and loving it! |
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| abraxas Regular Member Joined: 16/06/2020 Location: CanadaPosts: 99 |
Using EVAL for this seems like an expensive way to dereference the elements... It's surprising that MMBasic doesn't let us do what I tried to do in the first place. Since every variable is internally passed by reference it should be quite natural to add as a language feature. |
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| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3378 |
Still not sure exactly what you're looking for--something like a pointer in C, which could point to an element in one array, or to an element in another? PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
Wish I had the time to create a library of such things. No need to bloat MMBasic with functions that are rarely used. /* copying one array to another */ for(i = 0; i < Size; i++) { b[i] = a[i]; } Regards, Craig |
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