Scala dice program - scala

Question

I've just started Scala at University and we're currently just doing the basics but I'm moved ahead and want to try making some basic programs to get ahead. I'm currently trying to make a basic dice role guessing program.
I want to add in a feature to replay the game, the counter is to tell the user how many attempts to guess. I know I can add it in somewhere with counter += 1 just not sure where in the program to put it.
Currently compiling does nothing until I input something and I'm unsure why, then when I input something I don't get any results from the if statements it just terminates the program.
import scala.io.StdIn.readInt
import scala.util.Random
object GuessTheNumber {
def main(args: Array[String]): Unit = {
var play = true
var counter = 0 //Allows counting input
var responseGuess = readInt()
val numRange = Random.nextInt(12)
println("Enter your guess of the result of 2, 6 sided dice.")
while(play) {
if (responseGuess == numRange)
println ("You got it right!")
else if (numRange < responseGuess)
("Your guess was too large by" + (responseGuess - numRange) + " the corrrect answer was " + numRange)
else if (numRange > responseGuess)
( "Your guess was too small by" + (numRange - responseGuess) + " the correct answer was " + numRange)
else if (responseGuess < 1)
("Your guess is too small enter 2-12")
else if (responseGuess > 12)
("You entered an invalid number, 2 dice can only equate to a maximum of 12")
}
}
}

Answer 1

A couple things:
You should ask for a guess (the println) before you go get it from the input
All of your else if blocks were missing println statements
You aren't using your counter
Your numRange is incorrect, right now it would return 0 to 11 inclusive
I made those changes, and moved the readInt() inside the while loop to give people multiple chances to guess, once they guess the answer then the loop exited.
var play = true
val numRange = 2 + Random.nextInt(11)
while(play) {
println("Enter your guess of the result of 2, 6 sided dice.")
var responseGuess = readInt()
if (responseGuess == numRange) {
println ("You got it right!")
play = false
}
else if (numRange < responseGuess)
println("Your guess was too large")
else if (numRange > responseGuess)
println( "Your guess was too small")
else if (responseGuess < 2)
println("Your guess is too small enter 2-12")
else if (responseGuess > 12)
println("You entered an invalid number, 2 dice can only equate to a maximum of 12")
}
You can build off of this to get the functionality you need.

Answer 2

You had a few basic errors, but, a really good first attempt. I have included most of the comments in context for clarity. Here is a quick summary of some of the things that needed minor corrections
You forgot to include println in every else clause
You didn't reset the value of play variable causing your program to be stuck in an infinite loop. The while loop kept executing without asking user for any input giving the illusion that nothing was printing
The counter needs to be updated after every attempt within the loop
import scala.io.StdIn.readInt
import scala.io.StdIn.readChar
import scala.util.Random
object GuessTheNumber {
def main(args: Array[String]): Unit = {
var play = true
var counter = 1 //Allows counting input
// Start a loop. As long as the user says he wants to continue, we keep entering the loop
while (play) {
// The game is slightly more clear in my humble opinion if you ask him/her this question after every attempt.
// Otherwise you just have a blinking cursor on screen, without prompting user for input
println("Enter your guess of the result of 2, 6 sided dice.")
// Read his current response
val responseGuess = readInt()
// If you don't have `1 +`, then, 0 could be a potential result
val numRange = 2 + Random.nextInt(11)
if (responseGuess == numRange)
println(s"You got it right! in $counter attempts")
// You were missing println in each of the following cases. Hence the lack of response from your program, since,
// it didn't know you wanted it to print that response
else if (numRange < responseGuess)
println("Your guess was too large by " + (responseGuess - numRange) + " the correct answer was " + numRange)
else if (numRange > responseGuess)
println( "Your guess was too small by " + (numRange - responseGuess) + " the correct answer was " + numRange)
else if (responseGuess < 1)
println("Your guess is too small enter 2-12")
else if (responseGuess > 12)
println("You entered an invalid number, 2 dice can only equate to a maximum of 12")
println("Do you want to continue? (Y/N)")
// Now you are reading a character instead of an integer. Basically a Y or an N
play = readChar() match { // Not sure if you have gotten this far in your course. This syntax is referred to as pattern matching.
// Its basically the same as using if / else
case 'Y' | 'y' => true // If he enters Y or y, we assume he wants to continue.
case _ => // For any other input we abort
println(s"You tried $counter times") // When he does decide to quit, lets tell him how many times he tried
false
}
// After every attempt increment counter within your loop
counter += 1
}
}
}
Hope this helps.