data class mySubjectList(var name: String, var priority: String)

​

fun main() {

   val mySubjectList: List<mySubjectList> = listOf(

      mySubjectList("Java", "1"),

      mySubjectList("Kotlin", "2"),

      mySubjectList("C", "3")

   )

​

   // Creating a map and adding my own list of values in it.

   val myMap: Map<String, String> = mySubjectList.associate {

      Pair(it.priority, it.name)

   }

​

   println(myMap)

}

fun main() {

    val numbers = listOf("one", "two", "three", "four")

​

    println(numbers.associateBy { it.first().toUpperCase() })

    println(numbers.associateBy(keySelector = { it.first().toUpperCase() }, valueTransform = { it.length }))

}