是否可以将内存分配给具有特定索引的动态数组? [英] Is it possible to allocate memory to dynamic array with specific indexes?

问题描述

假设我有动态数组

type TCharArr = Array of byte;
type PcharArr = ^TCharArr;
var charArr: PcharArr;

我想用New(charArr);在堆中分配内存；

Which I want to allocate memory in Heap in the way of New(charArr);

但是，如何指定大小和索引?动态数组是否可以具有索引，例如.从512 ..到1024?

However, how can I specify size and indexes? Is it possible dynamic array to have indexes eg. from 512.. to 1024?

推荐答案

动态数组始终基于零.如果要使用具有不同基数的数组索引，则需要封装考虑到索引偏移量的数组访问.像这样:

Dynamic arrays are always zero based. If you want to use array indices with a different base, then you would need to encapsulate the array access accounting for the offset to the indices. Something like this:

const
  Offset = 512;

function GetValue(Index: Integer): Byte;
begin
  Result := Arr[Index - Offset];
end;

procedure SetValue(Index: Integer; Value: Byte);
begin
  Arr[Index - Offset] := Value;
end;

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