learn kotlin from java code example

Example 1: kotlin vs java

Kotlin is a language built on and entirely backwards-compatible with Java.
While Java is Object-Oriented first, Kotlin supports a blend
of OO and functional paradigms. For further information, refer to
kotlinlang.org

Example 2: kotlin

import java.util.*    // required import

fun randomDay() : String {
    val week = arrayOf ("Monday", "Tuesday", "Wednesday", "Thursday",
        "Friday", "Saturday", "Sunday")
    return week[Random().nextInt(week.size)]
}

fun fishFood (day : String) : String {
    return when (day) {
        "Monday" -> "flakes"
        "Wednesday" -> "redworms"
        "Thursday" -> "granules"
        "Friday" -> "mosquitoes"
        "Sunday" -> "plankton"
        else -> "nothing"
    }
}

fun feedTheFish() {
    val day = randomDay()
    val food = fishFood(day)
    println ("Today is $day and the fish eat $food")
}

fun main(args: Array<String>) {
    feedTheFish()
}