What literary devices are used in one thousand dollars by O Henry?

In "One Thousand Dollars" by O. Henry, the author uses irony when the protagonist's uncle leaves him $1,000 in his will on the condition that he must prove he can spend it wisely. The story also includes symbolism, as the money represents the uncle's final lesson to his nephew about the value of financial responsibility and character. The twist ending is another literary device that adds to the story's impact by revealing the true intentions behind the uncle's unusual bequest.