How are Dally and Johnny similar?

Though outwardly they seem to be polar opposites, Dally and Johnny share important similarities in The Outsiders that link them together throughout the novel. First, both came from abusive, neglectful families. Dally never mentions his mother, and the only time he mentions his father, he says,

Shoot, my old man didn’t give a hang whether I’m in jail or dead in a car wreck or drunk in the gutter.

Johnny says he prefers it when his father hits him, because then he feels recognized:

I walk in that house, and nobody says anything. I walk out, and nobody says anything. I stay away all night, and nobody notices. . . I ain't got nobody.

For both boys, then, the Greasers serve as a surrogate family. Johnny is the gang's pet, without whom he "would never have known what love and affection are." He is described as a "puppy," a soft and gentile soul who shouldn't be caught up in a gang. Dally, on the other hand, is a hardened street kid who has earned the gang's respect as its roughest, toughest member. He is described as having eyes "cold with hatred of the whole world." Johnny looks up to Dally as a kind of role model because of his ability to adapt without any family. Dally, conversely, takes Johnny under his wing and tries to toughen him up.
Each boy, in his own way, remains true to his character. This leads each of them to their deaths. Johnny, a sensitive lad who reads poetry with his best friend Ponyboy, is killed when he goes back into a burning church to save children, and the church roof collapses on him. Dally, who grew up on the "wild side" of New York and was first arrested at age 10, now distraught with grief over Johnny's death, consequently commits suicide by robbing a store and then provoking police officers into gunning him down. When Johnny is killed, Dally loses the one person in the world whom he truly loves. He cannot handle this, and with no parents to offer support, he reverts to what he instinctively knows: crime. The police can be seen as parental figures in this light. Dally is upset, and he wants to be punished for not being able to protect Johnny. Lacking a real parent/father to punish him, he turns to the only symbol of authority he knows.