In The Outsiders by S E Hinton, the "Greasers" and the "Socs" are two rival gangs from different sides of town. They despise each other and have been known to start a fight for no reason other than their rivalry. The main difference is that the Greasers always "fight fair" whereas the Socs do not.
In chapter 2, Johnny and Ponyboy talk to two Socs' girls, "Cherry" and Marcia, although initially Johnny is a little shy and, as Ponyboy, the narrator, says, "Johnny was always nervous around strangers." Johnny is a favorite of the Greasers, their "pet," and when he tells Dally to leave the girls alone, Dally and Ponyboy are completely taken by surprise because nobody would ever dare to cross Dally. "You just didn't tell Dally Winston what to do." Normally, Dally would have put anyone else in his place but not Johnny. Dally walks away. Johnny is a little embarrassed, especially because he actually thinks of Dally as his "hero," but having recognized that Dally was stepping over the line by harassing the girls, he speaks up.
Johnny is very nervous since he was previously attacked by the Socs without any provocation. They left Johnny for dead so when Two-Bit, one of their own members, jokingly comes up behind Johnny and Ponyboy, Johnny is noticeably scared. Ponyboy relates the story of what the Socs did to Johnny. Johnny is used to being beaten up by his own father and has had a very tough upbringing but, after the incident with the Socs, despite being "the most law-abiding of us," Johnny never leaves home without a "six-inch switchblade." The reader understands that Johnny has been pushed too far and when Ponyboy explains:
"He'd use it, too, if he ever got jumped again...Nobody was ever going to beat him like that again. Not over his dead body..."
The reader is under no illusion as to Johnny's fragile state of mind and ability to use the knife in extreme circumstances. It is also obvious that Johnny would need to be driven to the edge before he would use it. This foreshadows future tragic events.