Solved

Constructors, who is right?

Posted on 2004-08-19
1
192 Views
Last Modified: 2010-04-05
In the Delphi 7 help file it states:

"Create constructs an object. The purpose, size, and behavior of objects differ greatly. The Create constructor defined by TObject allocates memory but does not initialize data."

In Mastering Delphi 7 by Marco Cantu he says (on pg. 54) under Constructors:

"All of the data of the new instance is set to zero."

My question is, does the alllocated memory get initialized to zero, or not?

Regards,

Bill
0
Comment
Question by:wipnav
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 3

Accepted Solution

by:
KyleyHarris earned 50 total points
ID: 11848725
Yes, it does.

Any constructor defined by the key word constructor creates memory for the object and sets all bytes to 0. By saying it does not initialize data they mean that it does not set properties to predefined values. For Example. the default and stored keywords for published properties is not related;

property Color:TColor read FColor write FColor; default clGreen;

the constructor will not default the value to clGreen. This merely indicated that if the value equals the default value then do not stream it to a DFM

you still need to place

constructor createl
begin
  FColor := clGreen;
end;

otherwise it = 0
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

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…
In my programming career I have only very rarely run into situations where operator overloading would be of any use in my work.  Normally those situations involved math with either overly large numbers (hundreds of thousands of digits or accuracy re…
Monitoring a network: why having a policy is the best policy? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the enormous benefits of having a policy-based approach when monitoring medium and large networks. Software utilized in this v…
If you’ve ever visited a web page and noticed a cool font that you really liked the look of, but couldn’t figure out which font it was so that you could use it for your own work, then this video is for you! In this Micro Tutorial, you'll learn yo…
Suggested Courses
Course of the Month4 days, 1 hour left to enroll

630 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