Android Development with Kotlin

Data classes

Often, we create a class whose only purpose is to store data, such as, data retrieved from a server or a local database. These classes are the building blocks of application data models:

    class Product(var name: String?, var price: Double?) { 
 
       override fun hashCode(): Int { 
           var result = if (name != null) name!!.hashCode() else 0 
           result = 31 * result + if (price != null) price!!.hashCode()            else 0 
           return result 
       } 
 
       override fun equals(other: Any?): Boolean = when { 
           this === other -> true 
           other == null || other !is Product -> false 
           if (name != null) name != other.name else other.name !=  null -> false price != null -> price == other.price else -> other.price == null } override fun toString(): String { return "Product(name=$name, price=$price)" ...