GuessingGame.java

import java.util.*; // import everything in util

public class GuessingGame {
    public static int min = 0, max = 100; // set min to 0 and max to 100
    public static boolean running = true; // set this to false, and next time it loops, it will stop
    
    public static Scanner scanner = null; // this will be initialized by `main`
    public static Random rand = new Random(); // this will be used to get a random number later
  
    public static void main(String[] args) {
        scanner = new Scanner(System.in); // set it up to read input from the console
        
        while(running) { // repeat until running is set to false
            reset(); // reset the game
            
            System.out.println("Player is thinking of a random number between " + min + " and " + max); // print ranges for user
            
            while(true) { // repeat forever (or, until it is breaked by a break statement)
                int guess = getRandom(min, max); // get a random number between min and max
                System.out.println("\nComputer guesses: " + guess); // print out the computer's guess
                
                System.out.print("Player responds, this is (high, low, correct): "); // make an input prompt for the user
                String input = getInput().toUpperCase(); // get input and convert it to upper case
                
                if(input.startsWith("H")) { // the number is higher cause it starts with H
                    min = guess + 1; // so make this the minimum guess
                } else if(input.startsWith("L")) { // the number is lower
                    max = guess - 1; // so make this the maximum guess
                } else if(input.startsWith("C")) { // this guess is correct
                    break;
                } else {
                    System.out.println("Invalid option, try again.");
                }
            }
            
            System.out.println("\nComputer says: Good game, Dave."); // print "game over" message
            System.out.print("Play again? "); // make an input prompt again
            
            String choice = getInput().toUpperCase(); // get input and make it uppercase again
            
            if(choice.startsWith("Y")) { // the requirements say to check if it starts with Y or N
                running = true; // continue playing, the loop resets
                System.out.println(); // print empty line
            } else {
                running = false; // this will end the loop  
            }
        }
        
        System.out.println("Thanks for playing!"); // say "thanks" after the loop has ended
    }
    
    // call this function to reset the game
    public static void reset() {
        min = 0;
        max = 100;
    }
    
    // returns a string, the input from the console
    public static String getInput() {
        return scanner.nextLine();
    }
    
    // gets a random number between min and max
    public static int getRandom(int min, int max) {
        return rand.nextInt((max - min) + 1) + min;
    }
}