Scala js

println("Hello Scala.js") // In ES6: console.log("Hello Scala.js");

val lastNames = people.map(p => p.lastName)
// Or shorter:
val lastNames = people.map(_.lastName)

class Person(val firstName: String, val lastName: String) {
 def fullName(): String =
 s"$firstName $lastName"
}

val personMap = Map(
 10 -> new Person("Roger", "Moore"),
 20 -> new Person("James", "Bond")
)
val names = for {
 (key, person) <- personMap
 if key > 15
} yield s"$key = ${person.firstName}"

import org.scalajs.dom
import dom.document
def appendP(target: dom.Node, text: String) = {
 val pNode = document.createElement("p")
 val textNode = document.createTextNode(text)
 pNode.appendChild(textNode)
target.appendChild(pNode)
}

libraryDependencies += "org.scala-js" %%% "scalajs-dom" % "0.9.1" // (Triple %%%)

sbt run

sbt ~run

sbt fastOptJS