How do I create objects based on user input in Scala? - scala

Question

So I am trying to create a game and the user can has to choose 1 hero from a pool of heroes. How should I create the object of the user's chosen hero? Basically I am trying to create an object according to the user input
Edit:
I realize that just putting one paragraph is not enough and that I should add my code structure as well.
Currently I have a hero class and every other hero extends from this class, so I am trying to do something like this
class Hero {
}
class Bob extends Hero{ //Bob is one of the heroes that the user can choose
def skill1() { //the skills that Bob can use
}
}
class Player() {
val hero //player's hero option will be stored here
}
class Game { //gamedata will be stored here
val player: Player = new Player()
}
class Controller {
def selectHero { //this is where the user inputs a number from 1 to 10 and the app will create a hero object
}
}
I am stuck at the selectHero method and do not know how to proceed. I tried doing something like this:
val _hero1: Hero = (
if (option1 == 1) {
new Bob()
}
else if (option1 == 2) {
new James()
}
else if (option1 == 3) {
new Jimmy()
}
else {
null
}
)
But I ended up not being able to access their skills since parent classes cannot access the methods of child classes, can anyone help?

Answer 1

Here is an idea:
You can read from stdin a number and create as many heroes as you want until you want to break the loop. Using inheritance and polymorphism, your call to skills() will dynamically bound to the class of that hero object.
There are a lot of improvements you can do from here:
You still have to use a try-catch block to avoid a NumberFormatException, when inputing something that is not an Int.
You need to define toString() on every class that extends Hero. Currently when printing heroes, we get the objects, not their string representations.
You would be better with a Hero factory method than with a pattern match.
Consider making the Hero classes into objects if they are unique, or consider making them case classes if you need to pattern match on them.
import scala.collection.mutable
import scala.io.StdIn.readLine
import scala.util.control.Breaks.{break, breakable}
object Test extends App {
abstract class Hero {
def skills(): Unit
}
class Bob extends Hero {
def skills(): Unit =
println("This is Bob. His skills are partying like a Hero")
}
class James extends Hero {
def skills(): Unit =
println("This is James. His skills are drinking like a Hero")
}
class Jimmy extends Hero {
def skills(): Unit =
println("This is Jimmy. His skills are gaming like a Hero")
}
object Controller {
def selectHero(option: Int): Hero = option match {
case 1 => new Bob()
case 2 => new James()
case 3 => new Jimmy()
case _ => break
}
}
val heroes = mutable.Set.empty[Hero]
breakable {
while (true) {
val hero = Controller.selectHero(readLine().toInt)
hero.skills()
heroes += hero
}
}
println(heroes)
// process heroes further
println("done")
}
Output based on input:
1
This is Bob. His skills are partying like a Hero
2
This is James. His skills are drinking like a Hero
3
This is Jimmy. His skills are gaming like a Hero
4
HashSet(Test$James#337d0578, Test$Jimmy#61a485d2, Test$Bob#69d9c55)
done