Show a count of duplicate strings

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  14 years ago

  by et33

  et33

  , United States

  Joined 15 years ago

  Hi

  Help :)  Can someone show me (an easy way) how to list (in a listbox or stringlist etc.) a count of duplicate strings? 

  So far, I have looped through and added the strings to a listbox from a stringlist and the result i'm after is to show the list in the format in the 2nd column below (showing the number of duplicate strings). 

  Listbox1                  Listbox2

  examplea                 examplea 2

  exampleb                 exampleb 3

  examplea                 examplec

  examplec

  exampleb

  exampleb

  Hope that makes sense and any help will be greatly appreciated :|

  Ellen

  (Junior :))

   

   

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  14 years ago

  by CAMURPHY

  Craig Murphy

  Scotland, UK, United Kingdom

  Joined 15 years ago

  OK - first things first, I'm remote from my Delphi compiler, so this is off the top of my head...you may need to fix a couple of compile time typos :-)

  You'll need two TListBox components on a form and the following code behind a button:

  
  begin
  

    ListBox1.Sorted := true;

    count := 1;

    lastString := '';

    for i:=0 to ListBox1.Items.Count-1 do begin
      thisString := ListBox1.Items[i];
  

      if thisString = lastString then
        count := count + 1
      else
        if lastString <> '' then begin
           ListBox2.Items.Add(lastString + ' ' + IntToStr(count));
           count := 1;
        end;
  
  
  
  
  
  

        // Added

        lastString := thisString;
    end;
  

    if count > 1 then
      ListBox2.Items.Add(lastString + ' ' + IntToStr(count));
  
  end;
  

  The key is to sort the listbox, then look for duplicate strings that are adjacent to each other.

  Anyway, it's not the best way of weeding out duplicates, but it should give you enough to get you started.

  HTH

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  14 years ago

  by et33

  et33

  , United States

  Joined 15 years ago

  Hi,

  Thanks very much for that, it works (it seems i had the right idea, but just went around in circles :) )

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