Data Class

• Used for holding data with built-in toString(), equals(), hashCode() and copy()
• Requires at least one property in the primary constructor

data class User(val name: String, val age: Int)

Example usage:

val user1 = User("Alice", 25)
val user2 = user1.copy(age = 26) // Copy with modification
println(user1) // User(name=Alice, age=25)