根据表达式自动计算(二十四点游戏)

1:  引用单元 Comobj

procedure TForm1.Button1Click(Sender: TObject);
var
  s:string;
begin
  s:=self.Eval('('+edit1.Text+edit2.Text+edit3.Text+'/3*1000)/'+edit5.Text);
  self.Edit4.Text:=s;
end;

function TForm1.Eval(expStr:   string):   string;
var
  js:OleVariant;
begin
  js:=CreateOleObject('ScriptControl');
  js.Language:='JavaScript';
  Result:=js.Eval(expStr);
  js:=Unassigned;
end;