In "The Gift of the Magi" by O. Henry, the ending is indeed ironic. The story follows a young married couple, Della and Jim, who are living in poverty but are deeply in love. Each of them decides to sacrifice their most prized possession in order to buy a Christmas gift for the other. Della sells her beautiful long hair to buy a chain for Jim's prized pocket watch, while Jim sells his watch to buy combs for Della's hair.
The irony lies in the fact that each of them sacrifices something of great personal value to buy a gift for the other that complements the very thing they sacrificed. Della's hair, which she treasures, is cut off to buy a chain for Jim's watch, which is now useless because he sold it to buy combs for Della's hair. They end up with gifts that they cannot use, rendering their sacrifices seemingly in vain.
The story's ending is unexpected because while Della and Jim's intentions are sincere and heartfelt, their actions result in a situation where their sacrifices become ironically pointless. This twist at the end highlights the theme of the selflessness and unconditional love between the couple, despite their material poverty.
