Clearing an array - Printable Version

Clearing an array - Printable Version

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Clearing an array - patters - 2021-01-19

What is the recommended way to reset an array's contents? Do we have to run a FOR loop from 0 TO UBOUND and clear it element by element, or is there a neater way?
I see that the following doesn't work:

Code:
arrayName={}

RE: Clearing an array - Ljg701 - 2021-01-20

(2021-01-19, 11:47 PM)patters Wrote: What is the recommended way to reset an array's contents? Do we have to run a FOR loop from 0 TO UBOUND and clear it element by element, or is there a neater way?
I see that the following doesn't work:

Code:
arrayName={}

You could get the address of the start of the array and then use the MemSet method in the memcopy library to clear it quickly?

RE: Clearing an array - boriel - 2021-01-20

(2021-01-20, 12:30 PM)Ljg701 Wrote:
(2021-01-19, 11:47 PM)patters Wrote: What is the recommended way to reset an array's contents? Do we have to run a FOR loop from 0 TO UBOUND and clear it element by element, or is there a neater way?
I see that the following doesn't work:

Code:
arrayName={}

You could get the address of the start of the array and then use the MemSet method in the memcopy library to clear it quickly?

That's it. Exclamation

A proposal (I think even commented in this forum):

Code:
CLEAR array

Code:
CLEAR array, <new value>

but it's not implemented.

Instead you should perhaps use memset:

Code:
#include <memcopy.bas>

DIM myArray(10, 20) as UByte => 11 rows x 21 cols if using array_base 0

..

memset(@myArray(0, 0), 0, 11 * 21)

When dynamics array are implemented you could also ReDIM them... meanwhile...
Finally, remember you can assign (copy) entire arrays (myArray1 = myArray2) provided they are of the same shape and type.

RE: Clearing an array - patters - 2021-01-26

You have my vote for

Code:
CLEAR array

RE: Clearing an array - worcestersource - 2021-04-15

Just the clarify the syntax for copying an array, if mine has dimensions of 27,7, I'd type:

Code:
array1(27,7) = array2(27,7)

Because doing this doesn't appear to copy the data.

Thanks,

Steve

Ah. I figured it out. In the example above, it is literally as Boriel said.

Code:
array1 = array2

What's great with the quick code/compile cycle is that you can use trial and error to figure things out. Smile

Steve

RE: Clearing an array - boriel - 2021-04-16

(2021-04-15, 09:27 PM)worcestersource Wrote: Just the clarify the syntax for copying an array, if mine has dimensions of 27,7, I'd type:

Code:
array1(27,7) = array2(27,7)

Because doing this doesn't appear to copy the data.

Thanks,

Steve

Ah. I figured it out. In the example above, it is literally as Boriel said.

Code:
array1 = array2

What's great with the quick code/compile cycle is that you can use trial and error to figure things out.

Steve

This works. But array2 is always taking your memory. Consider using this within a function so once the function ends, array2 is freed from memory.

Code:
SUB initArray()

    DIM array2(...)

    array1 = array2

END SUB ' Here array2 is freed

Another solution is to use memset (if the array is NOT an array of strings), but these is a bit more complex.

Anyway, this will be available in the near future once I manage to implement DIM for dynamic arrays (as in SinclairBASIC), and REDIM.

RE: Clearing an array - worcestersource - 2021-04-16

Thanks Boriel. I think REDIM will be an elegant solution to what I'm trying to do.

Well worth a few coffees! Big Grin