Random number guessing game 456

Question

This code is working well, I am just fairly new to programming and am hoping someone more experienced can look it over and give me some pointers.

 * Author: Tyler Knight
 * Date Created: 02/07/2018
 * Program Purpose: Guessing game using
 * random numbers.
 **/
//Importing random and scanner classes
import java.util.Random;
import java.util.Scanner;
public class ElusiveNumbers {
 public static void main(String[] args) {
 //Declare variables
 Random num = new Random();
 int userInput;
 int answer;
 int count;
 int attempts;
 int restart;
 int terminate;
 int range;
 Scanner keyboard = new Scanner(System.in);
 //Whitespace
 System.out.println();
 System.out.println();
 try {
 //Greeting Message
 System.out.println("Welcome To Elusive Numbers!");
 //Whitespace
 System.out.println();
 //Prompt user to enter number range
 System.out.println("Enter the range of numbers you would like to guess from. EX: 5, 10, 100, 1000");
 //Whitespace
 System.out.println();
 //Allows User To Enter Range
 range = keyboard.nextInt();
 //Whitespace
 System.out.println();
 //Prompt user to enter in however many chances they would like to have
 System.out.println("Enter the amount of attempts you would like for this challenge");
 //Whitespace
 System.out.println();
 //Allows user to set amount of attempts
 attempts = keyboard.nextInt() - 1;
 //Whitespace
 System.out.println();
 //Prompt user to guess the number
 System.out.println("Enter a number between 1 and " + range);
 //Whitespace
 System.out.println();
 System.out.println();
 //Assign value to variables
 answer = num.nextInt(range) + 1;
 count = 0;
 /*
 * While the user input is not equal to the random generated number,
 * it will tell the user if their number was too high or too low,
 * it will also add 1 to the count variable every time user is wrong,
 * if the count variable becomes equal to 3 "Game Over" will display,
 * the user will then have the chance to try again or exit the game
 */
 do {
 //Assign value to variables
 userInput = keyboard.nextInt();
 restart = 1;
 terminate = 0;
 //If the count is higher than the attemps and user has not guessed the number, Game Over
 if (count >= attempts && userInput != answer) {
 //If user guess is too low, output Too Low!
 if (userInput < answer) {
 //Whitespace
 System.out.println();
 System.out.println("Too Low!");
 } 
 //If user guess is too high, output Too High!
 else if (userInput > answer) {
 //Whitespace
 System.out.println();
 System.out.println("Too High!");
 }
 //Whitespace
 System.out.println();
 System.out.println("Game Over!");
 //Whitespace
 System.out.println();
 System.out.println("To try again, type 1, to quit type 0");
 //Whitespace
 System.out.println();
 userInput = keyboard.nextInt();
 //Whitespace
 System.out.println();
 //If the user Chooses to restart the game will reset, Else the program will exit 
 if (userInput == restart) {
 count = 0;
 answer = num.nextInt(range) + 1;
 System.out.println("Enter the range of numbers you would like to guess from. EX: 5, 10, 100, 1000");
 //Whitespace
 System.out.println();
 range = keyboard.nextInt();
 //Whitespace
 System.out.println();
 System.out.println("Enter the amount of attempts you would like for this challenge");
 //Whitespace
 System.out.println();
 attempts = keyboard.nextInt() - 1;
 //Whitespace
 System.out.println();
 System.out.println("Enter a number between 1 and " + range + "\t");
 //Whitespace
 System.out.println();
 }
 else if (userInput == terminate) {
 return;
 }
 }
 // If the counter is at it's limit but the answer is correct it will not go to game over
 else if (count == 2 && userInput == answer) {
 System.out.println("Great Job!");
 System.out.println("To try again type 1, to quit type 0");
 userInput = keyboard.nextInt();
 //If user chooses to restart, everything will reset and game will start over
 if (userInput == restart) {
 count = 0; // Resets count
 answer = num.nextInt(range) + 1; // Resets random number
 System.out.println("Enter the range of numbers you would like to guess from. EX: 5, 10, 100, 1000");
 //Whitespace
 System.out.println();
 range = keyboard.nextInt();
 //Whitespace
 System.out.println();
 System.out.println("Enter the amount of attempts you would like for this challenge");
 //Whitespace
 System.out.println();
 attempts = keyboard.nextInt() - 1;
 System.out.println("Enter a number between 1 and " + range + "\t");
 //Whitespace
 System.out.println();
 } 
 else if (userInput == terminate) {
 return;
 }
 }
 else if (userInput > answer) {
 //Whitespace
 System.out.println();
 System.out.println("Too high!");
 //Whitespace
 System.out.println();
 count = count + 1;
 }
 else if (userInput < answer) {
 //Whitespace
 System.out.println();
 System.out.println("Too Low!");
 //Whitespace
 System.out.println();
 count = count + 1;
 }
 //If guess is equal to random number, user wins and chooses whether or not to restart.
 else if (userInput == answer) {
 System.out.println("Great Job!");
 System.out.println("To try again type 1, to quit type 0");
 userInput = keyboard.nextInt();
 if (userInput == restart) {
 count = 0; //Resets count
 answer = num.nextInt(range) + 1; //Resets random number
 System.out.println("Enter the range of numbers you would like to guess from. EX: 5, 10, 100, 1000");
 //Whitespace
 System.out.println();
 range = keyboard.nextInt();
 //Whitespace
 System.out.println();
 System.out.println("Enter the amount of attempts you would like for this challenge");
 //Whitespace
 System.out.println();
 attempts = keyboard.nextInt() - 1;
 //Whitespace
 System.out.println();
 System.out.println("Enter a number between 1 and " + range + "\t");
 //Whitespace
 System.out.println();
 } 
 else if (userInput == terminate) {
 return;
 }
 }
 }
 while (userInput != answer || count < attempts);
 }
 //Exception Handler
 catch (Exception all){
 System.out.println("Please enter a valid integer and try again.");
 }
 }

• internet_user: I don't know much about Java conventions, but I'm pretty sure //Assign value to variables is not a very good comment. (the //Whitespace is pretty useless too)
• RobotMan: Thanks dude, what would you suggest as a better comment for the variables then?
• internet_user: Maybe just nothing, it's not that hard to tell what it does.
• greybeard: (Welcome to CR!) (The code presented misses a line (easy to guess) at the top. In general, be easy on vertical screen space.)
• Simon Forsberg: Please do not update the code in your question to incorporate feedback from answers, doing so goes against the Question + Answer style of Code Review. This is not a forum where you should keep the most updated version in your question. Please see what you may and may not do after receiving answers .

Answer 1

• Don't Repeat Yourself
  With the 3rd occurrence of a sequence like add screen space, prompt user, parse an int, you should abstract that:

  /** Prompt for an int. */
  static int promptInt(Scanner keyboard, String prompt) {
   System.out.println();
   System.out.println(prompt);
   System.out.println();
   while (!keyboard.hasNextInt()) {
   keyboard.next();
   System.out.println("try again:");
   }
   return keyboard.nextInt();
  }
  

• use try-with-resources:

  try (Scanner keyboard = new Scanner(System.in)) {
   System.out.println("Welcome To Elusive Numbers!");
   range = promptInt(keyboard, "Enter the range of numbers "
   + "you would like to guess from. EX: 5, 10, 100, 1000");
   attempts = promptInt(keyboard, "Enter the amount of attempts "
   + "you would like for this challenge") - 1;
   answer = promptInt(keyboard, "Enter number to be guessed "
   + "between 1 and " + range) + 1;
  

• Don't Repeat Yourself
  the code repeats after If the user Chooses to restart

I got tired of scrolling through all those lines after that - just one more thing:
in the very end, you

• catch all Exceptions: dangerous
• tell the user "Please enter a valid integer and try again.", but terminate execution -
  such behaviour may raise scorns

• RobotMan: Thanks for taking the time to look at this and give some great advice!
• Rob Audenaerde: I like the repeating of 'Don't Repeat Yourself', well played :)

Answer 2

You are in a good place. Some advice to make your code better:

1. Start using an IDE

   The best one for Java developers, in my opinion, is IDEA IntelliJ. There is a community version, at the beginning of you coding adventure it'll be enough. I copied your code to my IDE and before I started reading it I get a message of potential duplicate code. It helps with extracting new methods and new classes, all that stuff. A proper IDE will do a lot of boring stuff for you.

2. Do not use comments

   Your code should be self-explanatory, especially at that small part of code. You can avoid commenting creating a proper class and methods structure.

   In your code, I created a new method:

   private static void addWhitespace() {
    System.out.println();
   }
   

   Small change but thanks to that I replaced all 33 of System.out.println(), some which was with the comment //Whitespace. We save some space and code is more readable.

3. Do not write complicated and long methods

   Your program has over 200 lines of code and there are no methods. It is hard to read. You can divide it into some parts, such as lines about starting messages to a user. You can extract it to separate method. Also, if you write some nested logic like for inside for inside if etc., divide it to different methods.

Ok, for the moment it should be enough. Please show next version of your code :)

• RobotMan: Thank you for the great advice. I see what your saying about putting my repetitive code into methods so I don't take up as much space. In my Computer Science class my instructor is really passionate about documentation in the code so that people that do not code can understand it. I do have to admit I have gone overboard with the comments though. Ill post an updated version here as soon as I get the chance.
• Rob Audenaerde: I disagree with 2. The code will show HOW something works, but not WHY it is chosen to be implemented this way. Comments are meant for people reading the code and understanding why it is coded up in this fashion. For example, a comment could be 'I choose to use an ArrayList because of the o(1) get-performance'. I agree with leaving out comments that describe how the code works if that is trivial.
• RobotMan: Right, I get what your saying. That's what i'm finding difficult in college, they are teaching us how to use logic to solve problems but not really how to write good code. My first example of this code worked, but there was a completely better way to write it.

Answer 3

what i would really recommend would be to split your code into sepreate code blocks... that increases the readability and reduces complexity...

do {
 ...
 if (count >= attempts && userInput != answer) {
 //If user guess is too low, output Too Low!
 if (userInput < answer) {
 printTooLow();
 } 
 //If user guess is too high, output Too High!
 else if (userInput > answer) {
 printTooHigh();
 }
 printGameOver();
 userInput = keyboard.nextInt();
 //If the user Chooses to restart the game will reset, Else the program will exit 
 if (userInput == restart) {
 reStart(); 
 }
 ...
 }
 ...
}while (userInput != answer || count < attempts);

that allows you to re-use code. you can use printTooHigh() later again...

and that really seperates the code into relevant blocks (in your case: methods)

NOTE: the code above is just an example how you could adjust your code.