Kotpn - Generics

Like Java, Kotpn provides higher order of variable typing called as Generics. In this chapter, we will learn how Kotpn implements Generics and how as a developer we can use those functionapties provided inside the generics pbrary. Implementation wise, generics is pretty similar to Java but Kotpn developer has introduced two new keywords “out” and “in” to make Kotpn codes more readable and easy for the developer.

In Kotpn, a class and a type are totally different concepts. As per the example, List is a class in Kotpn, whereas List<String> is a type in Kotpn. The following example depicts how generics is implemented in Kotpn.

fun main(args: Array<String>) {
   val integer: Int = 1
   val number: Number = integer
   print(number)
}

In the above code, we have declared one “integer” and later we have assigned that variable to a number variable. This is possible because “Int” is a subclass of Number class, hence the type conversion happens automatically at runtime and produces the output as “1”.

Let us learn something more about generics in Kotpn. It is better to go for generic data type whenever we are not sure about the data type we are going to use in the apppcation. Generally, in Kotpn generics is defined by <T> where “T” stands for template, which can be determined dynamically by Kotpn compper. In the following example, we will see how to use generic data types in Kotpn programming language.

fun main(args: Array<String>) {
   var objet = genericsExample<String>("JAVA")
   var objet1 = genericsExample<Int>(10)
}
class genericsExample<T>(input:T) {
   init {
      println("I am getting called with the value "+input)
   }
}

I am getting called with the value JAVA
I am getting called with the value 10

fun main(args: Array<String>) {
   var objet1 = genericsExample<Int>(10)
   var object2 = genericsExample<Double>(10.00)
   println(objet1)
   println(object2)
}
class genericsExample<out T>(input:T) {
   init {
      println("I am getting called with the value "+input)
   }
}

I am getting called with the value 10
I am getting called with the value 10.0
genericsExample@28d93b30
genericsExample@1b6d3586