He can be considered a hero of sorts in that he does stand up for what which he believes. Regardless of whether or not his ideas are logical, he is forming ideas and opinions and standing up for them. There is no doubt the act of quitting is impulsive and there is not doubt that, initially, Sammy does it for the girls. In fact, he admits that he hopes to become their "unsuspected hero" (1420). When Sammy pitches his work apron to the counter, he is alone with no one applauding him. In addition, it is safe to assume that the girls are never aware of his action. However, this is the kind of thing that creates a teenager. Bravado coupled with an attitude is what teenage angst is all about and Updike captures these characteristics perfectly in Sammy. Sammy does not have any...

Sammy's desire is simply to be a hero for the girls but his action results in much more than that. He becomes a hero in his own mind for standing up for what he considers something important. This makes him a well-rounded character because it helps readers identify with him even though he is unaware of how significant his action is at the moment.
Work Cited

Updike, John. "A&P." The Norton Anthology of Short Fiction. New York W.W. Norton and Company. 1981. pp. 1416-1421.