Solved

Only a doubt about creating component in run time

Posted on 2006-07-11
6
175 Views
Last Modified: 2010-04-05
My doubt is that I am creating two components with the same name but in different procedures, can I have a problem with this?


See this code



Procedure OpenDB;

  procedure DeleteTMPDB(code: Integer);
  Var
    TQ : Tadoquery;
  Begin
    TQ : Tadoquery.Create(nil);
    ... etc
    Try
     Finally
      FreeAndNil(TQ)
    End
  End

Var
  TQ : Tadoquery;
Begin

  Begin
    TQ : Tadoquery.Create(nil);
    ... etc
    Try
       With TQ do
       Begin
          Sql.Add('Select * from table');
          Open;
       End;
       While TQ.Not Eof do
       Begin
          DeleteTMPDB(TQ.FieldByName('ID').AsInteger);
          TQ.Next;
       End
     Finally
      FreeAndNil(TQ)
    End
  End

End
0
Comment
Question by:hidrau
[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
  • 4
  • 2
6 Comments
 
LVL 26

Expert Comment

by:Russell Libby
ID: 17081695

The variables are scoped differently, so there isn't an issue.

Russell

0
 
LVL 26

Expert Comment

by:Russell Libby
ID: 17081747
Eg, an example to test scope of variables:

procedure TestScope;

  procedure TestInnerScope;
  var S:      String;
  begin
     ShowMessage(S);
  end;

var S:        String;
begin

  S:='Hello world';
  TestInnerScope;

end;
0
 
LVL 1

Author Comment

by:hidrau
ID: 17081789
so, I could tell that they are connected by procedure, is it?
0
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!

 
LVL 26

Accepted Solution

by:
Russell Libby earned 500 total points
ID: 17081810
For further info, the Delphi help on the topic "Scope" reads as follows:

Naming conflicts

When one block encloses another, the former is called the outer block and the latter the inner block. If an identifier declared in an outer block is redeclared in an inner block, the inner declaration overrides the outer one and determines the meaning of the identifier for the duration of the inner block. For example, if you declare a variable called MaxValue in the interface section of a unit, and then declare another variable with the same name in a function declaration within that unit, any unqualified occurrences of MaxValue in the function block are governed by the second, local declaration. Similarly, a function declared within another function creates a new, inner scope in which identifiers used by the outer function can be redeclared locally.
0
 
LVL 26

Expert Comment

by:Russell Libby
ID: 17081854
>> so, I could tell that they are connected by procedure, is it?

Not sure I follow what you are asking... The only connection is in the fact that the DeleteTMPDB can only be called from within OpenDB, as DeleteTMPDB is a nested block. But the variable TQ  (because of the inner scope redeclaration) is 2 individual variables, where the usage depends on the scope (block level being executed)

Russell
0
 
LVL 1

Author Comment

by:hidrau
ID: 17081984
Yeah, TQ are two different variables and none of them affects each other. That's all that I would like to know. :)
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
Delphi - replicating a form 8 93
How to build JSON File in Delphi 6 3 71
how to change, disabled button color FMX ? 1 51
Using MMsystem To change audio input 1 20
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…
In this tutorial I will show you how to use the Windows Speech API in Delphi. I will only cover basic functions such as text to speech and controlling the speed of the speech. SAPI Installation First you need to install the SAPI type library, th…
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…
In a recent question (https://www.experts-exchange.com/questions/29004105/Run-AutoHotkey-script-directly-from-Notepad.html) here at Experts Exchange, a member asked how to run an AutoHotkey script (.AHK) directly from Notepad++ (aka NPP). This video…

726 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