wares behind plate-glass made a shop window conspicuous. Soapy took a cobblestone and dashed it through the glass. People came running around the corner, a policeman in the lead. Soapy stood still, with his hands in his pockets, and smiled at the sight of brass buttons.

One of the dictionary definitions of irony is:

a state of affairs or an event that seems deliberately contrary to what one expects and is often amusing as a result.

Smashing a big plate-glass window with a cobblestone is not contrary to what Soapy expects, but it is contrary to the reader's expectations. And it is amusing as a result, even though it is outrageous.

Every event in the story is ironic. It is ironic that a penniless bum would walk into an elegant restaurant with the intention of ordering some of the most expensive items on the menu. When he ends up eating at a cheap restaurant, he has to stuff himself in order to run up the bill high enough to make the management want to call the cops. And it is ironic that he eats a lot of cheap fodder when he had been planning on wild duck, Chablis, and Camembert cheese.

On the opposite side of the street was a restaurant of no great pretensions. It catered to large appetites and modest purses. Its crockery and atmosphere were thick; its soup and napery thin. Into this place Soapy took his accusiveshoes and telltale trousers without challenge. At a table he sat and consumed beefsteak, flapjacks, doughnuts and pie. 

It is ironic that Soapy has to eat so much food that he can't try his restaurant trick again after being thrown out on his ear. He wouldn't be able to consume any more food.

It is ironic that the woman Soapy tries to molest would be just waiting for some man to approach her. It is ironic that he steals an umbrella from a man who had stolen it himself. And, of course, the final irony is that Soapy gets arrested just when he decides to reform.

Everybody has bad days like that. They may not be so colorful or dramatic, but there are days when nothing seems to go right. All the stoplights turn red just as we get to them. Some women call them "Bad Hair Days." Life itself is ironic.

This is the story of Soapy, a homeless man in New York City who is trying to get arrested because winter is coming and he wants to get free room and board in jail.

The irony here is just that when Soapy wants to get arrested and taken to jail, he can never manage to get a police officer to arrest him.  But then he decides to change his ways and quit being a bum.  As soon as he does that, he gets arrested.

I think it is ironic that Soapy finally gets what he had wanted earlier in the story, but now he no longer wants that.

"The Cop and the Anthem" contains situational irony. This is the type of irony in which the opposite of what the reader thinks will happen actually does happen. For example, when Soapy is carrying out small misdeeds such as stealing an umbrella or shouting loudly to feign drunkenness, he thinks that he will be arrested. He wants to be arrested to spend winter in the comfort of a jail cell on Blackwell's Island rather in the park. However, no matter which minor laws he breaks, he can not get a cop to arrest him. It is only when he is doing the right thing, which is standing near a church and hearing music that fills him with the desire to lead a good life, that he is arrested. When he is near the church, he should not be arrested, but he is. Therefore, the opposite of what the reader expects occurs.

"The Cop and the Anthem" follows the misadventures of Soapy, a homeless man, while winter begins its approach. Due to the harshness of the winter conditions, Soapy determines to get himself arrested, so as to enjoy the shelter that incarceration would provide. He embarks on various attempts to get himself in trouble with the law, but each time it ends in failure.

However, O. Henry is known for his twist endings, and this story is no exception. In his despair, Soapy determines to turn his life around, get a job, and strive to make something out of himself. However, it is after he has come to this epiphany, loitering outside an old church, that a policeman comes around and arrests him.

This, then, is the great irony at the end of the story. All of Soapy's various attempts to get himself in trouble end in failure. It is only later, after he has experienced his change of heart, that he is finally put under arrest (but it is at a point when he no longer has any desire to be arrested at all).

The key irony is that Soapy, the main character, is trying to get thrown into jail so that he can have a warm place to stay but cannot seem to get arrested for a series of attempts at being a minor criminal.  Soapy hears an anthem coming from a church that reminds him of his better days and decides not to rely on the charity of the police and a warm jail cell, but to turn himself around to become a productive citizen.  It is at that precise moment he is arrested for loitering by the church.  Just as Soapy decides he doesn't want to be arrested after all, he is arrested.  The minor ironies occur throughout the story.  He thinks if he goes into a restaurant and orders a big meal, then doesn't pay, he'll get arrested.  However, he is turned away from the restaurant before he can order.  Next, he goes to shop and throws a rock through the window, then waits for a policeman.  When the cop shows up, the cop doesn't believe that a man guilty of the crime would just stand there and wait to be arrested so he doesn't think Soapy did it.  When Soapy accosts a woman, thinking he'll get arrested for the things he says to her, she turns out to be a prostitute who hears his words as a business proposition.  When he tries to steal a man's umbrella, it turns out that the man had stolen the umbrella himself and thinks Soapy is the rightful owner.  When he tries to act like he is drunk, someone thinks he's just being a prankster.  He doesn't get arrested until he no longer wants to be arrested. 

In O Henry's "The Cop and the Anthem", we have Soapy, our resident ne'er-do-well looking to get a stay on Riker's Island (New York City jail) for the winter.  In his endeavors to be incarcerrated, we see him do a number of illegal activities, never terribly destructive to be consistent with his nature.  Try as he might, he just can't get arrested and thus does not get his desired room and board for the winter.

Then comes the anthem.  A church plays a hymn that takes Soapy to a spiritual epiphany and he upbraiads himself for his unscrupulous ways and decides to live a life that will see him as a productive citizen.  The irony comes that just when Soapy decided to turn his life around, the cop decided that the bum had lingered outside the church long enough and charge him with vagrancy.  Soapy is sent to jail for three months.  Irony often imitates life as it does here.