Give some stream of consciousness and then the answer. Alan Douglas Ruck (born July 1, 1956) is an American actor. He played Cameron Frye, Ferris Bueller's hypochondriac best friend in John Hughes' Ferris Bueller's Day Off (1986), and Stuart Bondek, the lecherous, power-hungry member of the mayor's staff in the ABC sitcom Spin City. His other notable films include Bad Boys (1983), Three Fugitives (1989), Young Guns II (1990), Speed (1994), Twister (1996), and Kickin' It Old Skool (2007). In 2016, he co-starred with Geena Davis in an updated Fox TV adaptation of William Peter Blatty's best-selling novel The Exorcist.

Answer this question: who played cameron in ferris bueller's day off?
The relevant information is: He played Cameron Frye, Ferris Bueller's hypochondriac best friend in John Hughes' Ferris Bueller's Day Off (1986), and Stuart Bondek, the lecherous, power-hungry member of the mayor's staff in the ABC sitcom Spin City.
Therefore, the answer is Alan Douglas Ruck.