How is personification used in the short story "A&P"?

John Updike's 1961 short story "A&P" contains many examples of figurative language. Simile and metaphor are the most commonly used, but there are several examples of personification, as well. 

The story is told in the first person point of view and describes the narrator's experience when three girls in bathing suits enter the grocery store and are chastened by the manager for their inappropriate clothing. The narrator, Sammy, decides to take a stand and quit his job in defense of the manager's treatment of the girls. 

When Sammy makes his grand exit after announcing that he is quitting, there are three examples of personification:

"One advantage to this scene taking place in summer, I can follow this up with a clean exit, there's no fumbling around getting your coat and galoshes, I just saunter into the electric eye in my white shirt that my mother ironed the night before, and the door heaves itself open, and outside the sunshine is skating around on the asphalt." 

The first example in this quote is the door "heaving" itself open. Heaving, or raising or lifting with effort, is something only a person or animal could do. An automatic door simply opens or closes, it doesn't strain with the effort. The effect this word choice creates is that the A&P is more than just a building, it's a type of microcosm or heartbeat of the town. 

Another example of personification in this quote is the sunshine skating on the pavement. This suggests that the sun is wavering, the heat rising from the asphalt. It is also a playful word choice for the sun, skating is a graceful and fun activity. It suggests that the narrator is pleased with his choice to stand on principle and quit because of the way the manager treated the girls. 

In the last paragraph, the narrator states: "My stomach kind of fell as I felt how hard the world was going to be to me hereafter."  It could be argued that the narrator has personified the world in this quote, describing it as a taskmaster, or an enemy. The narrator is realizing that growing up presents many challenges. He is understanding that his actions have consequences, harder consequences than when he was very young. This is evidenced in the manager, Lengel, telling him how his parents are going to be displeased with his actions. By looking back, he sees that the A&P will go on without him, and he hasn't made a big difference by taking a stand.