Solved

passing array as a parameter

Posted on 2004-04-12
1
798 Views
Last Modified: 2010-04-05
hi, everyone.

my code is this:

procedure TForm1.Beregn(var Vinner: array of TKort);
var
j: integer;
begin
SetLength(Vinner,j);
dosomething with Vinner;
SetLength(Vinner,j);
end;

I call this metdhod this way:

procedure TForm1.Test;
var
Vinner: array of TKort;
begin
Beregn(Vinner);
Continue with my Vinner array that has been changed inside Beregn-method.
end;


But the thing is... I get an error everytime i try to call the SetLength method inside the Beregn method. Incompatible types, it says. Then I thought... is this a pointer-issue?
0
Comment
Question by:Darth_helge
1 Comment
 
LVL 20

Accepted Solution

by:
Madshi earned 500 total points
ID: 10804708
When using an open "array of" array parameter like that you can't change the length of the array. The reason is simple:

procedure TForm1.Test;
var Vinner: array [0..9] of TKort;
begin
  Beregn(Vinner);
end;

What should Delphi do now, if you call SetLength? Do you see the problem? That's why calling SetLength is not supported.

However, you can solve the problem this way:

type TVinnerArr = array of TKort;

procedure TForm1.Beregn(var Vinner: TVinnerArr);
var j: integer;
begin
  SetLength(Vinner,j);
  dosomething with Vinner;
  SetLength(Vinner,j);
end;

procedure TForm1.Test;
var Vinner: TVinnerArr;
begin
  Beregn(Vinner);
end;

This works.
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

Suggested Solutions

The uses clause is one of those things that just tends to grow and grow. Most of the time this is in the main form, as it's from this form that all others are called. If you have a big application (including many forms), the uses clause in the in…
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…
This Micro Tutorial demonstrates using Microsoft Excel pivot tables, how to reverse engineer competitors' marketing strategies through backlinks.
Internet Business Fax to Email Made Easy - With  eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, f…

863 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

19 Experts available now in Live!

Get 1:1 Help Now