What type of collection should I use? delphi

Question

I want to use one keys for two values in Delphi some thing like this

TDictionary<tkey, tfirstvalue,tsecondvalue>;

Answer 1

Put your values into a compound structure like a record. Then use that record type as your dictionary value type.

Answer 2

Delphi has not Tuple type. I don't know your purpose but may dynamic array of record type help.

Type
Tdict_ = reocord
 tkey:integer;
tfirstvalue,Tsecondvalue :string;
end;
var
Tdict:array of tdict_
...
procedure adddata(Tkey:integer;tfirstvalue:string;Tsecondvalue :string); 
begin
     setlength(tdict,length(tdict)+1);
    tdict[length(tdict)-1].tkey:=tkey;
    tdict[length(tdict)-1].tfirstvalue:=tfirstvalue;
    tdict[length(tdict)-1].tsecondtvalue:=tsecondvalue;    
end;

but you must write your own "find" function for return index of array .

for example

    Function find(tkey:integer):integer;
    var i:Integer;
    begin
     for i:=0 to length(Tdict)-1 do
     if tdict[i].tkey=i then
       begin
        result:=i;
        break;
       end;
    end;

    Function deletecalue(tkey:integer):integer;
    var i,j:Integer;
    begin
     i:=find(tkey)
        for j:=i to length(Tdict)-2 do
           tdict[j]:=tdict[j+1];
        setlength(tdict,length(tdict)-1);

    end;

if keys are strings type must be changed, but it will be slow for huge date .

Also read This: https://github.com/malcolmgroves/generics.tuples

Answer 3

TDictionary<TKey, TPair<TFirstValue, TSecondValue>>, as @RudyVelthuis commented, is possible and works. However, TPair (found in System.Generics.Collections) is not meant for that - the two values are named Key and Value, which doesn't make sense here. We should make a copy of TPair, which could be named TTuple.

You can then do MyDictionary.Add('key', TTuple<string, string>.Create('firstvalue', 'secondvalue'));

Since it is implemented as a record (value type), there is no need to free it.