How the act 3 in the importance of being earnest is dramatic or comedy?

Wilde's ironies explode in the whirlwind last-minute revelations. As Jack (or Ernest) says, "it is a terrible thing for a man to find out suddenly that all his life he has been speaking nothing but the truth." The various conflicts from lies are resolved since they turn out (for the most part) not to be lies after all. Jack truly is Ernest, Algernon truly is his mischievous brother. But if the lies in the play are true, then what can we make of the supposed truths? On the flip side, we see that