Sodapop is one of the main characters of the novel The Outsiders. He is the middle of the Curtis boys, and therefore, brother of Ponyboy, the main character in the story.
Sodapop is perceived by others as a cool, charming figure. Ponyboy is jealous of how charming he is, and he is also considered to be "movie-star handsome." Ponyboy idolizes him and relies heavily on him.
Sodapop is quite relaxed and laid-back, and he rarely shares his problems. Instead, he is always ready to help others, particularly Ponyboy. He is also vital in bringing his brothers together, and decreasing their fighting.
The character changes little throughout the story. One of the changes we see is the fact that we learn more about what troubles him. This involves the fighting between his brothers and his relationship with Sally.