Question

How to write the 7 Boom game. If a number is divided by 7 or includes the digit 7, the user writes Boom in Scala

Answer 1

import scala.io.StdIn.readLine

object SevenBoomGame {

  def containsSeven(num: Int): Boolean =
    num.toString.contains('7')

  def isBoom(num: Int): Boolean =
    num % 7 == 0 || containsSeven(num)

  def getUserInput(prompt: String): String =
    Option(readLine(prompt)).fold("")(_.trim)


  def processTurn(expected: Int, input: String): Boolean = {
    val lower = input.toLowerCase
    val shouldBoom = isBoom(expected)

    if (shouldBoom) {
      if (lower != "boom") {
        println(s"$input (should be Boom)")
        println("YOU LOSE!")
        return false
      }
    } else {
      if (lower == "boom") {
        println(s"Wrong move! It was $expected")
        println("YOU LOSE!")
        return false
      }

      input.toIntOption match {
        case Some(value) if value == expected => // OK
        case _ =>
          println(s"Wrong move! It was $expected")
          println("YOU LOSE!")
          return false
      }
    }

    true
  }

  def runGame(): Unit = {
    val startInput = getUserInput("Enter a number from which you want to start the game (-1 to exit): ")

    val startNum = startInput.toIntOption.getOrElse(-1)
    if (startNum == -1) return

    var current = startNum

    while (true) {
      val input = getUserInput("Enter a number (or Boom): ")

      if (input == "-1") {
        println("Game Over!")
        return
      }

      if (!processTurn(current, input))
        return

      current += 1
    }
  }

  def main(args: Array[String]): Unit = runGame()
}




/*
run:

Enter a number from which you want to start the game (-1 to exit): 6
Enter a number (or Boom): 6
Enter a number (or Boom): Boom
Enter a number (or Boom): 8
Enter a number (or Boom): 9
Enter a number (or Boom): 10
Enter a number (or Boom): 11
Enter a number (or Boom): 12
Enter a number (or Boom): 13
Enter a number (or Boom): Boom
Enter a number (or Boom): 15
Enter a number (or Boom): 16
Enter a number (or Boom): Boom
Enter a number (or Boom): 18
Enter a number (or Boom): 19
Enter a number (or Boom): 20
Enter a number (or Boom): 21
21 (should be Boom)
YOU LOSE!

*/

 

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