Guessing A Number

I used Eclipse until I realized that I needed to use NetBeans to unlock MOOC.FI’s upcoming week exercises. NetBeans has components and methods ready to use whereas I had to make my own methods in Eclipse.

This is Week 2 Exercise #41. I did every exercises in Eclipse until end of Week 2 including this one. This exercise to me is mostly about creating methods and applying them. My Eclipse codes won’t pass in NetBeans, but I feel that my codes in Eclipse give a better idea of what methods are.

Listing out all the bits of this exercise on what we are to do.

• create drawNumber method that generates a random number between 0 and 100
• have an user to guess a number
• let user know that number is either lesser or greater and or user guessed right!
• Let user repeat guesses while drawNumber stays the same
• print the number of guesses attempted along with the answer

I didn’t come up with this code on my own. I used stackoverflow. This is the way to generate a random number. Setting that drawNumber() method. The drawn number is set to varible num. Notice how I put down int after public static instead of void. Remember void means no returned value. In this method, we are returning a drawn number. so it’s an int.

// Generates random number
public static int drawNumber() {
    int num =(int)(Math.random() * 100 + 1);
    System.out.println(num);
    return num;
}

The next step is creating a method guess() that has reader reading user’s guess. Again, user is guessing a number and this will return an integer value. I am putting down int instead of void. The guess is returned as guess.

// Read user's guess
public static int guess() {
    Scanner reader = new Scanner(System.in);
    System.out.print("Guess a number: ");
    int guess = Integer.parseInt(reader.nextLine());
    return guess;
}

The third step is notifying user whether his/her guess is right. If not then let him/her know that the guessing number is either greater, or lesser. Isn’t that like a boolean? Let’s do this in boolean fashion. I am putting down boolean instead of void. Thanks to briennakh, that was her idea. I am going to name this method checkGuess(int guess, int num). Using same varibles and values from two other methods above. It is important to repeat what type of values or varibles they are. Java is static.

// Check guess against given number
public static boolean checkGuess(int guess, int num) {
    if (guess == num) {
        System.out.println("You have guessed it!");
        return true;
    } else if (guess > num) {
        System.out.println("The guessing number is greater.");
        return false;
    } else {
        System.out.println("The guessing number is lesser.");
        return false;
    }
}

Time to make the main method! The first step inside the method is draw the number. That’s how Guess A Number game starts. Again, repeat the type of value or variable. int num = drawNumber(); and the number is drawn. I added System.out.println(num); because I want to make sure drawNumber() works. Could do that inside drawNumber() method, but why not here too. Could remove them after knowing that they do work! I am going to lay them out now and add other perks.

// Run program
public static void main(String[] args){
    int num = drawNumber();
    System.out.println(num);
    System.out.println();
    int guesses = 5;
    while(guesses > 0) {
        int guess = guess();
        boolean correct = checkGuess(guess, num);
        if (correct) {
            break;
        }

        guesses--;
        System.out.println("You have " + guesses + " guesses left");
        System.out.println("Try again!");
        System.out.println();
    }
}

I want to limit the number of guesses to 5. Note guess and guesses are two different things. guess is the value of user’s guessing number. guesses is the number of how many guessing attempts user had made. int guess is the input given from guess() by a user. Notice how guess has an type defined by int. That’s Java. I am going to add boolean for checkGuess(guess, num), giving its a varible correct to use in a conditional statment. The loop ends in two different ways. If guesses reach down to 0, then it has expired, or if user guessed right then break;.

Let’s put all methods together and get an overview!

package week2;

import java.util.Scanner;

public class week2_ex41{

    // Generates random number
    public static int drawNumber() {
        int num =(int )(Math.random() * 100 + 1);
        System.out.println(num);
        return num;
    }

    // Read user's guess
    public static int guess() {
        Scanner reader = new Scanner(System.in);
        System.out.print("Guess a number: ");
        int guess = Integer.parseInt(reader.nextLine());
        return guess;
    }

    // Check guess against given number
    public static boolean checkGuess(int guess, int num) {
        if (guess == num) {
            System.out.println("You have guessed it!");
            return true;
        } else if (guess > num) {
            System.out.println("The guessing number is greater.");
            return false;
        } else {
            System.out.println("The guessing number is lesser.");
            return false;
        }
    }

    // Run program
    public static void main(String[] args){
        int num = drawNumber();
        System.out.println();
        int guesses = 5;
        while(guesses > 0) {
            int guess = guess();
            boolean correct = checkGuess(guess, num);
            if (correct) {
                break;
            }

            guesses--;
            System.out.println("You have " + guesses + " guesses left");
            System.out.println("Try again!");
            System.out.println();
        }
    }
}

We have a Guess A Number game!