Difference between revisions of "TStringList"

From Lazarus wiki
(added a data dictionary example from the forum.)
(See also)
 
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* [[doc:rtl/classes/tstringlist.html|TStringList doc]]
 
* [[doc:rtl/classes/tstringlist.html|TStringList doc]]
 
* [[TStringList-TStrings Tutorial]]
 
* [[TStringList-TStrings Tutorial]]
* [[TBufStream | example of saving a TSringList to disk faster than the SaveToFile method can]]
+
* [[TBufStream | example of saving a TStringList to disk faster than the SaveToFile method can]]

Latest revision as of 15:02, 29 August 2021

English (en) suomi (fi) polski (pl)

A TStringList is a datatype that can hold an arbitrary length list of strings. The strings in a TStringList are accessible as concatenated plain text or as a series of strings. Functionality is also provided for key-value pair access.

Inheritance
  • TObject - Base class of all classes.
    • TPersistent, IFPObserved - Base class for streaming system and persistent properties - Interface implemented by an object that can be observed.
      • TStrings - Class to manage arrays or collections of strings
        • TStringList - Standard implementation of the TStrings class.

TStringList adds sorting functionality to TStrings by adding properties Sorted, Duplicates and CaseSensitive and methods like Find to facilitate speeded search within a list.

Example
  // get a value from file FILNAM filled with key=value pairs 
function GetValueFromFile( filnam: string, key: string ): string;
var
  lst: TStringList;
  v: String;
begin
  lst := TStringList.Create();
  lst.CaseSensitive := false;
  lst.Duplicates := dupIgnore; // do not add duplicates
  lst.Sorted := true;
  lst.LoadFromFile( filnam );
  v := lst.Values[ key ];
  lst.Free();
  result := v;
end;

TStringlist also has a 'builtin' data dictionary mode, here is an example provided by forum user Remy Lebeau

   uses
     ..., Classes;
    
   var
     SL: TStringList;
     Value: Integer;
   begin
     SL := TStringList.Create;
     try
       SL.Add('VarName=99');
       ...
       Value := StrToInt(SL.Values['VarName']);
       ...
     finally
       SL.Free;
     end;
   end;


See also