CODEWITHSUNDEEP
delphiloopsvariables
Mathmathou
Mathmathou

Reputation: 373

Delphi : dynamic variable names?

Long time reader, first time poster, I'm turning to you because I so many times found answers to my questions here, that I'm sure this one will be just a formality for this great community :)

My question might seem odd, even newbish, but I'm building an application for parsing text lines with urls.

A the beginning of the code, the first step is to determine how many urls there are in the text block. I do it by using the "copy" function from the beginning till the end of the text block, looking for the tag "a href=" tag.

This works fine.

Here is the code :

Tag := '<a href="';
                    Longueur := Length(ArtistNBSource);
                    Result := 0;
                        For i := 1 to Longueur do
                            begin
                                Copied := Copy(ArtistNBSource,i,Length(Tag));
                                if Copied = Tag then inc(Result)
                            end;
                    ARTIST_COUNT := Result;

Now, depending on the number of urls found, I'm going to loop through the text block.

What I would like to avoid is things like this...

if Result : 1 do
     begin
         some instruction
     end
else if Result = 2
     begin
          other instruction
     end
else if Result = 3....

...because with a maximum of 5 url possible in the text block, that would give me a veryyyyy long code.

What I imagined was this :

First of all, I declare variables up to the maximum known possible.

var
AUPOS1, AUPOS2, AUPOS3, AUPOS4, AUPOS5, ANPOS1, ANPOS2, ANPOS3, ANPOS4, ANPOS5, ia : Integer;

As the parsing patern is fixed, I imagined this :

For ia := 1 to ARTIST_COUNT do
                        begin
                            (AUPOS+IntToStr(ia)):= Pos('">', ArtistNBSource);
                            (AURL+IntToStr(ia)) := Copy(ArtistNBSource,11,(AUPOS+IntToStr(ia))-11);
                            Delete(ArtistNBSource,1,(AUPOS+IntToStr(ia))+1);
                            (ANPOS+IntTostr(ia)) := Pos('</a>', ArtistNBSource);
                            (ANAME+IntToStr(ia)) := Copy(ArtistNBSource,1,(ANPOS+IntToStr(ia))-1);
                            Delete(ArtistNBSource, 1,(ANPOS+IntToStr(ia))+4);
                        end;

The ia variable matching the number of loops AND the variables names for each loop, I thought I could auto increment the variables names and assign their values to the previously declared variables.

But of course this does not work :)

My question :

Do any of you see a solution out of this ?

Am I condemned to writing the 'if then' long sequence, or can I dynamically adjust variable names through the loop ?

Thank you all in advance for any comment that might give me a clue of what direction to follow.

Cheers

Mathmathou.

Upvotes: 1

Views: 2208

Answers (1)

user2692263
user2692263

Reputation: 535

I would recommend having just one variable - a dictionary/hash table and then have the 'dynamic variable names' be keys in that dictionary and the values be what you would store in those 'dynamically named' variables.

Here is a tutorial about dictionaries:

http://beensoft.blogspot.se/2008/09/simple-generic-dictionary-tdictionary.html

Upvotes: 1

Related Questions