Array with pointer variable access

Thomas Jonsso

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Array with pointer variable access

Hi!

I've got a question with and pointer as array variable:

type
Data_Rec = record
V : byte;
end;

ryData_Rec = array[1..10,1..10,1..10] of Data_Rec;

ptrData_Rec = ^ryData_Rec;

var DataRecptr : ptrData_Rec;

----
new(DataRecptr)
----

Assume I want to read/write the [1,1,1] : array value of V; how do I
access it?
I assumed it would be DataRecPtr^[1,1,1].V .......

/tj

Frederic Bonro

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:Array with pointer variable access

Quote

Thomas Jonsson wrote:
> type
> Data_Rec = record
> V : byte;
> end;

> ryData_Rec = array[1..10,1..10,1..10] of Data_Rec;

> ptrData_Rec = ^ryData_Rec;

> var DataRecptr : ptrData_Rec;

> ----
> new(DataRecptr)
> ----

> Assume I want to read/write the [1,1,1] : array value of V; how do I
> access it?
> I assumed it would be DataRecPtr^[1,1,1].V .......

And what makes you think it isn't DataRecPtr^[1,1,1].V ?

Mike Copela

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:Array with pointer variable access

Quote

> Type Data_Rec = record
> V : byte;
> end;
> ryData_Rec = array[1..10,1..10,1..10] of Data_Rec;
> ptrData_Rec = ^ryData_Rec;
> var DataRecptr : ptrData_Rec;

> ----
> new(DataRecptr)
> ----

> Assume I want to read/write the [1,1,1] : array value of V; how do I
> access it?
> I assumed it would be DataRecPtr^[1,1,1].V .......

Yes, that's how. Didn't you try it? (It's easy enough to do...)
This is an impractical record definition to use, since you can define
the array type as Byte and leave out the Data_Rec definition. Unless
this is an academic or school exercise, you're doing much more than this
seems to require.

G?ran Andersso

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:Array with pointer variable access

"Thomas Jonsson" <Thomas.Jons...@mailbox.hogia.net> skrev i meddelandet
news:38A14A5B.8BAFD8E1@mailbox.hogia.net...

Quote

> Hi!

> I've got a question with and pointer as array variable:

> type
> Data_Rec = record
> V : byte;
> end;

> ryData_Rec = array[1..10,1..10,1..10] of Data_Rec;

> ptrData_Rec = ^ryData_Rec;

> var DataRecptr : ptrData_Rec;

> ----
> new(DataRecptr)
> ----

> Assume I want to read/write the [1,1,1] : array value of V; how do I
> access it?
> I assumed it would be DataRecPtr^[1,1,1].V .......

> /tj

It is.

I pasted the code in TP7, added a Begin, Write(); and an End.

The only problem was a missing ; at the end of the new() statement.
The compiler reports this at the next line. Did that fool you?

--
/GreenGhost
---
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