Solved

Delphi, Arrays returned by functions must be freed?

Posted on 2014-10-13
2
321 Views
Last Modified: 2014-10-13
Hello,
I've got a doubt about the need of freeing arrays returned by functions.
Here's my array type and function:

type
  TStringArray = array of string; 

function GetHelloStringArray() : TStringArray;
begin
     SetLength(Result,5);
     Result[0] := 'H';
     Result[1] := 'E';
     Result[2] := 'L';
     Result[3] := 'L';
     Result[4] := 'O';
end;

Open in new window


Suppose I'm using the GetHelloStringArray function as shown here:

procedure TForm1.Button1Click(Sender: TObject);
var
  MyArray : TStringArray;
begin
  MyArray := GetHelloStringArray();
  //DO SOMETHING HERE
  //...
  SetLength(MyArray,0) // <--- IS THIS NEEDED?
end;

Open in new window


Is the SetLength command needed or can be avoided?
Thanks to everyone.
0
Comment
Question by:ExDev001
2 Comments
 
LVL 33

Accepted Solution

by:
ste5an earned 500 total points
ID: 40376707
Ask the oracle itself (Delphi) :)

program Project9;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.SysUtils;

type
  TStringArray = array of string;

function GetHelloStringArray(): TStringArray;
begin
  SetLength(Result, 5);
  Result[0] := 'H';
  Result[1] := 'E';
  Result[2] := 'L';
  Result[3] := 'L';
  Result[4] := 'O';
end;

var
  MyArray: TStringArray;

begin
  ReportMemoryLeaksOnShutdown := True;
  MyArray := GetHelloStringArray();
  WriteLn('Press any key...');
  ReadLn;

end.

Open in new window


MyArray is a normal data type, thus you don't need to do anything. I would be different, when this is a reference type, where only the reference is managed by Delphi, but not the object or memory where the references points to.
0
 

Author Closing Comment

by:ExDev001
ID: 40377212
Thanks alot for clarification!
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article explains how to create forms/units independent of other forms/units object names in a delphi project. Have you ever created a form for user input in a Delphi project and then had the need to have that same form in a other Delphi proj…
Introduction Raise your hands if you were as upset with FireMonkey as I was when I discovered that there was no TListview.  I use TListView in almost all of my applications I've written, and I was not going to compromise by resorting to TStringGrid…
Hi friends,  in this video  I'll show you how new windows 10 user can learn the using of windows 10. Thank you.
Both in life and business – not all partnerships are created equal. As the demand for cloud services increases, so do the number of self-proclaimed cloud partners. Asking the right questions up front in the partnership, will enable both parties …

920 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

16 Experts available now in Live!

Get 1:1 Help Now