"A & P" by John Updike was written early in his career. In an interview, Updike claimed that Sammy was somewhat autobiographical for the author when he was writing the story: 1960s.
The protagonist Sammy serves as the narrator of the story.
This is Sammy's story. The reader learns that the story is being told as a flashback to an event which has negatively impacted Sammy. Updike uses his story to exemplify to universal themes: generation gaps and choices and their consequences.
Updike uses the events in the story to illustrate the differences in generations. Sammy represents the new generation that in the not too distant future will support more individual freedom. This freedom will come from the idea that the person should make decisions for himself about what he wears, the type of haircut he chooses, and what he believes about aspects of life. This is the "dawning of a new day" as the songwriter wrote. Sammy's stance against Lengel to quit his job demonstrated Sammy's first time to face off against the old standards.
One of the important motifs illuminated is making choices and understanding that their are consequences for them. Sammy is only nineteen. His experiences have been limited to his school and work in his small town grocery store. He chooses to quit his job to point up the injustice of the treatment of the girls by Lengel. In fact, his quitting had a duel purpose: to make a statement to Lengel and to impress the girls. Neither of which occurred. Lengel thinks Sammy is a foolish young kid, and the girls do not even see or hear Sammy quitting his job.
To point up this theme again, the girls choose to go into the grocery store dressed inappropriately for the time period. In brief swimming suits and barefooted, even in today's standards of "No shoes, no shirts, no service," indicates that in public places there is a standard dress code. In the 1960s, women were still wearing hats, gloves, and dressing up to go to town to shop. Men were wearing suits and ties at work. The girls' choices had consequences; they were told not to come back to the store dressed indecently:
'That makes no difference,' Lengel tells her, and I could see from the way his eyes went that he hadn't noticed she was wearing a two-piece before. 'We want you decently dressed when you come in here.'
Every choice has an aftereffect.
Lengel choose to embarrass the girls by dressing them down in front of the grocery workers and other customers. He was already upset about other things. He certainly could have handled the situation in a less humiliating and threatening way. Possibly, his actions might stand as a misuse of power. At any rate, Lengel suffered his consequence when one of his best workers chooses to quit based on Sammy's principles of following the golden rule. Lengel espoused to be a Sunday School teacher. His judgment should have pointed him in the right direction. Lengel reaped what he sowed.
The ending of the story finds the main character without a job and with that uneasy feeling of "deer in the headlight" emotions. Unfortunately, the reader never knows what happens to Sammy and his lost job.