Kotlin hashCode() and equals()
data class User(val name: String, val age: Int) fun main(args: Array<String>) { val u1 = User("John", 29) val u2 = u1.copy() val u3 = u1.copy(name = "Amanda") println("u1 hashcode = ${u1.hashCode()}") println("u2 hashcode = ${u2.hashCode()}") println("u3 hashcode = ${u3.hashCode()}") if (u1.equals(u2) == true) println("u1 is equal to u2.") else println("u1 is not equal to u2.") if (u1.equals(u3) == true) println("u1 is equal to u3.") else println("u1 is not equal to u3.") }