unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Buttons, ComCtrls;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    RichEdit1: TRichEdit;
    Edit2: TEdit;
    BitBtn1: TBitBtn;
    procedure BitBtn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.BitBtn1Click(Sender: TObject);
var
    i,j,n2,n,n1,index:Integer;
    str,str1,str2:string;
    s:array[1..10] of string;
    res:array[1..100] of string;
begin
    index:=0;
    str:=RichEdit1.Text;
    str1:=Edit1.Text;
    str2:=Edit2.Text;
    n2:=Length(str2);
    n:=Length(str);
    n1:=Length(str1);
    for i:=1  to n2 do //替換後的字元新增到文本當中
        s[i]:=Edit2.Text[i];
    for i:=1 to n do
       if str[i]=str1 then
          begin
          for j:=1 to n2 do
              begin
              index:=index+1;
              res[index]:=s[j];
              end;
          end
       else
           begin
             index:=index+1;
             res[index]:=str[i];
           end;


      RichEdit1.Text:='';
      for i:=1 to 100 do
         RichEdit1.Text:=RichEdit1.Text+res[i];
end;

end.
 

執行結果：