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TSortedCollection.Search function

Member of TSortedCollectionIn unit Objects

Search for item with given key.

Declaration

pascal
function Search(Key: Pointer; var Index: Sw_Integer): Boolean; virtual

Description

Search looks for the item with key Key and returns the position of the item (if present) in the collection in Index.

Instead of a linear search as TCollection does, TSortedCollection uses a binary search based on the keys of the objects. It uses the Compare function to implement this search.

If the item is found, Search returns True, otherwise False is returned.

Errors

None.

See also

Example: ex36

pascal
Program ex36;

{ Program to demonstrate the TSortedCollection.Insert method }

Uses Objects,MyObject,MySortC;
 { For TMyObject,TMySortedCollection definition and registration }

Var C : PSortedCollection;
    M : PMyObject;
    I : Longint;

Procedure PrintField (Dummy: Pointer;P : PMyObject);

begin
  Writeln ('Field : ',P^.GetField);
end;


begin
  Randomize;
  C:=New(PMySortedCollection,Init(120,10));
  C^.Duplicates:=True;
  Writeln ('Inserting 100 records at random places.');
  For I:=1 to 100 do
    begin
    M:=New(PMyObject,Init);
    M^.SetField(Random(100));
    C^.Insert(M)
    end;
  M:=New(PMyObject,Init);
  Repeat;
    Write ('Value to search for (-1 stops) :');
    read (I);
    If I<>-1 then
      begin
      M^.SetField(i);
      If Not C^.Search (M,I) then
        Writeln ('No such value found')
      else
        begin
        Write ('Value ',PMyObject(C^.At(I))^.GetField);
        Writeln (' present at position ',I);
        end;
      end;
  Until I=-1;
  Dispose(M,Done);
  Dispose(C,Done);
end.

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.