System.DynArraySetLength
Delphi
procedure DynArraySetLength(var a: Pointer; typeInfo: Pointer; dimCnt: NativeInt; lengthVec: PNativeint);
C++
extern DELPHI_PACKAGE void __fastcall DynArraySetLength(void * &a, void * typeInfo, NativeInt dimCnt, PNativeInt lengthVec);
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
procedure function |
public | System.pas System.hpp |
System | System |
Description
Resizes a dynamic array.
DynArraySetLength resizes each dimension of a dynamic array. See the description of the input parameters in the following table:
| Parameter | Description |
|---|---|
a
|
Pointer to the target dynamic array. |
typeInfo
|
Type information of the target array (used to compute the size of an element). |
dimCnt
|
The number of dimensions of the target array. |
lengthVec
|
An array with integers that indicate the size of each dimension. |
The newly allocated memory is filled with zeros.
- 2D dynamic array illustration
- Note: In Delphi, you can use the SetLength procedure instead of DynArraySetLength.
Example
In the following code, the dynamic array A is resized using the DynArraySetLength procedure:
type
T2DDynamArray = array of array of String;
var
A: T2DDynamArray;
Len: array [0 .. 1] of Integer;
begin
Len[0] := 3; // Length of the dimension 0
Len[1] := 4; // Length of the dimension 1
DynArraySetLength(Pointer(A), TypeInfo(T2DDynamArray), 2, PLongInt(@len[0]));
end.
The same operation can be done with the SetLength procedure (this is the recommended approach):
begin
SetLength(A, 3, 4);
end.