What examples of literary elements appear in The Catcher in the Rye?
This is a very broad question, so I'll give a few examples related to symbolism, point of view, and stream-of-consciousness narration.
Point of view
The Catcher in the Rye is told in first-person point of view from the perspective of Holden Caulfield, the story's primary character. Holden tells the story a few months after the events take place, and he seems to be in a hospital. This is shown early in the first chapter when Holden says,
I'll just tell you about this madman stuff that happened to me around last Christmas just before I got pretty run-down and had to come out here and take it easy.
Additionally, Holden often slips into stream-of-consciousness narration, a technique in which a character's thoughts flow uninterrupted. An example of this occurs when he talks about his brother Allie's baseball mitt. After explaining his brother wrote poetry on his baseball mitt so "he'd have something to read when he was in the field and nobody was up to bat," Holden describes his feelings for his brother, making connection after connection. He does this several times in the novel, including his description of the museum and his thoughts about sex. A clue as to when he's using this technique is paragraph length. If the paragraph extends for more than a page, there's a good chance J.D. Salinger is employing the stream-of-consciousness technique.
There are many symbols throughout The Catcher in the Rye. Symbolism occurs when an object stands for something else. While there are many famous examples of symbolism in The Catcher in the Rye (including Holden's red hunting hat and the ducks in Central Park), one symbol I find particularly striking occurs early in the novel when Holden refuses to throw a snowball at a car or hydrant because both look "so nice and white." This whiteness Holden refuses to disturb symbolizes his desire not to spoil anything that seems pure. This idea runs throughout the novel.