Holden finds a lot of things ironic about his prep school, Pencey. One of the clearest instances of situational irony to be found, in his opinion, is the regular thievery among the students:
Pencey was full of crooks. Quite a few guys came from these very wealthy families, but it was full of crooks anyway. The more expensive a school is, the more crooks it has—I’m not kidding.
Pencey is full of thieves despite the wealth and privilege of its pupils. This is an example of situational irony because one might expect a prestigious school like Pencey, which has a strict and rigid honor code, to be safe and honest. Holden is regularly dissatisfied with the behavior of his classmates because he sees Pencey as an institution that teaches and enforces “phony” behavior. It teaches its pupils how to behave in an adult world that Holden believes is run and populated by liars and deceivers. He’s emphasizing how true he thinks this is by noting that a lot of the students are “crooks” when they get there, as they come from “these very wealthy families.” The inherited wealth of the other students doesn’t stop them from stealing from each other, which belies Holden’s opinion that privilege and wealth don’t ensure good behavior or good morals. In fact, he’s suggesting here that having more money actually makes his classmates more inclined to be criminals, as “the more expensive a school is, the more crooks it has.”
At the very beginning of The Catcher in the Rye, Holden Caulfield makes a statement filled with situational irony and containing an allusion to Charles Dickens. He begins his narration by saying:
If you really want to hear about it, the first thing you’ll probably want to know is where I was born, and what my lousy childhood was like, and how my parents were occupied and all before they had me, and all that David Copperfield kind of crap, but I don’t feel like going into it, if you want to know the truth.
The situational irony here lies in the fact that Holden is saying one thing and then immediately doing another. Despite stating that he doesn't want to talk about himself, Holden proceeds to tell a book-length story that goes deeply into his private experiences and thoughts. This contradiction points to his teenage lack of self-awareness, as he fails to recognize that he is indeed "going into it" by narrating his story. The reader, however, quickly understands what’s happening, especially as Holden’s reluctance to speak quickly dissolves.
Holden's allusion to David Copperfield by Charles Dickens adds to the passage’s irony, as Holden expands on what he’s “not” going to do and then does exactly that. David Copperfield is a novel that tells the story of the protagonist David Copperfield’s development and personal growth, much like Holden’s own story. By dismissing the idea of telling his life story as being "David Copperfield kind of crap," Holden states his disdain for the genre while participating in it himself. This reference is also notably meta: it’s almost as though Holden is aware that he’s a character in a book.
Throughout The Catcher in the Rye Holden reads voraciously but uses words and references incorrectly, often making them up when he can't remember the exact term he's looking for. These malapropisms are situationally ironic, since Holden often tries to present himself in a distinguished, sophisticated manner but actually ends up highlighting his own naivety and inexperience. For example, he lies to Sunny, the sex worker, about an operation on his “clavichord,” and when she asks what it is, he says:
“The clavichord?” I said. “Well, actually, it’s in the spinal canal. I mean it’s quite a ways down in the spinal canal.”
In this scene, Holden is very uncomfortable, as he’s changed his mind about having sex with the sex worker Maurice has sent to his room. He is trying to extract himself from this awkward situation with the excuse that he's had a recent operation on his clavicle. However, he gets the word wrong, calling it a “clavichord,” which is actually an old stringed instrument that was used throughout the Renaissance period and is somewhat similar to the piano.
Holden's mistake here—and the many others mistakes like it—is his attempt to appear smart and cultured, even when he doesn't fully understand the terms he uses. Because Holden struggles with loneliness and feeling isolated, he seeks validation through intellectual pretensions like this one. He could have made up any excuse or simply told the woman that he wasn’t interested in sex, but instead, he decided to try to bamboozle her with his medical knowledge. This kind of malapropism lends the novel a certain comedic lightness. This is especially the case whenever malapropisms crop up in situations in which Holden seems at his most despondent. Finally, this moment also shows the reader Holden's vulnerability, drawing attention to the gap between his aspirations and his disappointing reality. His linguistic blunder makes him a more relatable and endearing character, as it suggests that—ironically enough—he himself is sometimes the same kind of “phony” that he so despises.