考虑这个课程:
unit Unit2;
interface
type
TTeste = class
private
texto: string;
public
function soma(a, b: integer): string;
end;
implementation
procedure TForm2.Button1Click(Sender: TObject);
var
teste: TTeste;
begin
teste:= nil;
teste.texto:= '';//access violation
showmessage(teste.soma(5, 3));//no access violation
end;
{ TTeste }
function TTeste.soma(a, b: integer): string;
begin
result:= (a+b).ToString;
end;
end.
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它真的有效吗?为什么?var崩溃了但功能没有,它是否像类功能一样工作?