Объектно ориентированные технологии

type
 TString = class
  size: integer;
  value: string;
 
  function getValue: string;
  procedure setValue(value: string);
  constructor create(s: string);
  destructor destroy;
  procedure print;
  procedure input;
  function equal(s: TString): boolean;
  procedure join(s: TString);
  procedure insert(ch: char; index: integer);
end;
 
function TString.getValue: string;
begin
 self.getValue := self.value;
end;
 
procedure TString.setValue(value: string);
begin
 if self.value <> value then
  self.value := value;
 self.size := length(value);
end;
 
constructor TString.create(s: string);
begin
 self.setValue(s);
end;
 
destructor TString.destroy;
begin
 self.setValue('');
end;
 
procedure TString.print;
begin
 write(self.value);
end;
 
procedure TString.input;
var
 temp: string;
begin
 read(temp);
 self.setValue(temp);
end;
 
function TString.equal(s: TString): boolean;
begin
 self.equal := (self.getValue = s.getValue);
 end;
 
procedure TString.join(s: TString);
var
 temp: string;
begin
 temp := self.getValue + s.getValue;
 self.setValue(temp);
end;
 
procedure TString.insert(ch: char; index: integer);
var
 temp: string;
begin
 temp := self.getValue;
 temp[index] := ch;
 self.setValue(temp);
end;
 
 
var
 s: TString;
 
begin
 s := TString.create('test');
 s.print; // test
 s.insert('x', 3);
 s.print; // text
 s.destroy;
end.