Appointing methods in Java - java

I have created a simple project for my self, and now i am trying to integrate a code that will make the program restart when i enter "restart" in the console. To do that I have created a second method in my program that contains exactly the same code as my main method but now i want to appoint the second method which i don't know how to do. All help is appreciated!
here is my code so far:
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("guess the number between 1 and 9");
int random = (int)(Math.random() * 9 + 1);
int value = 0;
do{
value = scanner.nextInt();
if (value != random){
System.out.println("Try again");
}
}
while(value != random);
System.out.println("You guessed the number");
if(value == random){
System.out.println("Would you like to restart?");
String reset = scanner.nextLine();
if (reset.equals("restart")){
/*
*I need some code here
*/
}
}
}
public static void restart(String[] args){
Scanner scanner = new Scanner(System.in);
System.out.println("guess the number between 1 and 9");
int random = (int)(Math.random() * 9 + 1);
int value = 0;
do{
value = scanner.nextInt();
if (value != random){
System.out.println("Try again");
}
}
while(value != random);
System.out.println("You guessed the number");
if(value == random){
System.out.println("Would you like to restart?");
String reset = scanner.nextLine();
if (reset.equals("restart")){
}
}
}

You should just call main() in "if (reset.equals("restart")){..."
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("guess the number between 1 and 9");
int random = (int)(Math.random() * 9 + 1);
int value = 0;
do{
value = scanner.nextInt();
if (value != random){
System.out.println("Try again");
}
}
while(value != random);
System.out.println("You guessed the number");
if(value == random){
System.out.println("Would you like to restart?");
String reset = scanner.nextLine();
if (reset.equals("restart")){
main(args); // restart you code
return;
}
}
}
or use following code:
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
do{
System.out.println("guess the number between 1 and 9");
int random = (int)(Math.random() * 9 + 1);
int value = 0;
do{
value = scanner.nextInt();
if (value != random){
System.out.println("Try again");
}
}
while(value != random);
System.out.println("You guessed the number");
System.out.println("Would you like to restart?");
String reset = scanner.nextLine();
}
while(reset.equals("restart"));
}

Try something like this,
In your code,
you have been mess up code, and need to break down according to requirement, a
Also, need to take care if user want to restart then again game will be played.
This things overcome by below code,
static int value;
static int random = (int)(Math.random() * 9 + 1);
static Scanner scanner = new Scanner(System.in);
public static void main(String[] args) {
do{
System.out.println("Enter Your Guesses :");
value = scanner.nextInt();
if(value == random){
System.out.println("Exactly Match : " + value + " == " + random);
System.out.println("Would you like to restart?");
String reset = scanner.next();
if (reset.equals("restart")){
restart();
}
}else{
System.out.println("Try again");
}
}while(value != random);
System.out.println("You guessed the number");
}
public static void restart(){
do{
random = (int)(Math.random() * 9 + 1);
}while(value == random);
}

Related

Need to validate int; hasNextInt isn't working

I'm working on a homework problem of creating a guessing game. I've got that part working, but we have to validate the input. I've tried using hasNextInt, but I keep getting an error saying "int cannot be dereferenced" and points to the "!guess.hasNextInt" code.
I've tried many iterations, but I still get the same error. The code I'm including is just my most recent try.
How do I get hasNextInt to work or how else should I validate the input?
import java.util.Scanner;
public class GuessNumber {
public static void main(String[] args) {
int num = (int) (Math.random() * 101);
Scanner input = new Scanner(System.in);
System.out.println("Welcome to my Guessing Game!");
int guess = -1;
//Loop goes as long as guess doesn't equal num
while (guess != num) {
System.out.print("Guess a number between 1 and 100: ");
guess = input.nextInt();
//Validates input
while (!guess.hasNextInt()) {
System.out.println("Invalid response, try again.");
in.next();
}
if (guess == num)
System.out.println("Correct!");
else if (guess < num)
System.out.println("Your guess was too low");
else
System.out.println("Your guess was too high");
}
}
}
i fixed the code:
public static void main(String[] args) {
int num = (int) (Math.random() * 101);
System.out.println(num);
Scanner input = new Scanner(System.in);
System.out.println("Welcome to my Guessing Game!");
int guess = -1;
//Loop goes as long as guess doesn't equal num
while (guess != num) {
System.out.print("Guess a number between 1 and 100: ");
guess = input.nextInt();
if (guess == num) {
System.out.println("Correct!");
break;}
else if (guess < num)
System.out.println("Your guess was too low");
else
System.out.println("Your guess was too high");
//Validates input
while (!input.hasNextInt()) {
System.out.println("Invalid response, try again.");
input.next();
}
}
}
if the user guessed the number the game ends using break
in while (!guess.hasNextInt()) you were using a integer where it's expect the Scanner input
If you want to parse your number you can use Integer.parseInt() method as shown. Also you are using hasNextInt() incorrectly. You are also not storing in.next() value in any variable.
import java.util.Scanner;
public class GuessNumber {
public static void main(String[] args) {
int num = (int)(Math.random() * 101);
Scanner input = new Scanner(System.in);
System.out.println("Welcome to my Guessing Game!");
int guess = -1;
//Loop goes as long as guess doesn't equal num
while (true) {
System.out.print("Guess a number between 1 and 100: ");
String numberString = input.nextLine();
//Validates input
try {
guess = Integer.parseInt(numberString);
if (guess == num) {
System.out.println("Correct!");
break;
} else if (guess < num)
System.out.println("Your guess was too low");
else
System.out.println("Your guess was too high");
} catch (Exception e) {
System.out.println("Invalid response, try again.");
}
}
}
}

Why is my do-while loop not working?

When I compile, that try to enter (y) to play again my do - while is not working, it takes me out of the loop.
import java.util.Scanner;
public class HiLo {
public static void main(String[] args) {
// Creating a play again variable
String playAgain = "";
// Create Scanner object
Scanner scan = new Scanner(System.in);
// Create a random number for the user to guess
int theNumber = (int)(Math.random() * 100 + 1);
int guessNumber = 0;
do
{
System.out.println("Guess a number between 1 - 100: ");
while (guessNumber != theNumber)
{
guessNumber = scan.nextInt();
if (guessNumber > theNumber)
{
System.out.println("Sorry, try again too high!");
}
else if (guessNumber < theNumber)
{
System.out.println("Sorry, try again too low!");
}
else
{
System.out.println("Congrats, you got it!");
}
}
System.out.println("Would you like to play again (y/n)?");
playAgain = scan.next();
} while (playAgain.equalsIgnoreCase("y"));
System.out.println("Thank you for playing! Goodbye.");
scan.close();
}
}
Change the code as below: (You just need to update the variables inside the loop)
public static void main(String[] args) {
// Creating a play again variable
String playAgain = "";
// Create Scanner object
Scanner scan = new Scanner(System.in);
// Create a random number for the user to guess
int theNumber = 0;
int guessNumber = 0;
do
{
// new lines to be added
theNumber = (int)(Math.random() * 100 + 1);
guessNumber = 0;
System.out.println("Guess a number between 1 - 100: ");
while (guessNumber != theNumber)
{
guessNumber = scan.nextInt();
if (guessNumber > theNumber)
{
System.out.println("Sorry, try again too high!");
}
else if (guessNumber < theNumber)
{
System.out.println("Sorry, try again too low!");
}
else
{
System.out.println("Congrats, you got it!");
}
}
System.out.println("Would you like to play again (y/n)?");
playAgain = scan.next();
} while (playAgain.equalsIgnoreCase("y"));
System.out.println("Thank you for playing! Goodbye.");
scan.close();
}
Here is the execution of code on Jshell:
The reason the program is not working is because the do-while loop does one iteration before it gets to the "while" part. In your case, the program successfully finishes the loop after a user correctly guesses the number. Your program breaks because after that you are requiring the user to enter 'y' to continue endlessly without letting them guess a number. If they guess a number, the program terminates.

Not sure how to do a while loop in this situation

I am writing a program to take the input for a sequence
import java.util.Scanner;
public class FibonacciCode {
public static void main(String[] args) {
System.out.println("Enter a number");
int count, number0 = 0, number1 = 1, loop = 0;
Scanner userInput = new Scanner(System.in);
count = userInput.nextInt();
while(loop > count)
{
System.out.print(number0 + ", ");
int sum = number0 + number1;
number0 = number1;
number1 = sum;
loop++;
}
}
}
This should be a usable implementation:
public class Menu {
public static void main(String[] args) {
Scanner a = new Scanner(System.in);
boolean orderCompleted = false;
while(!orderCompleted) {
printMenu();
String orderString = a.nextLine();
int order = Integer.parseInt(orderString);
int total = 0;
if(order == 1) {
} else if(order == 2) {
} else if(order == 3) {
} else if(order == 4) {
} else if(order == 5) {
}
System.out.println("Would you like to order more? Press 'y' to continue or 'n' to finish order.");
orderString = a.nextLine();
if(orderString.equals("n")){
orderCompleted = true;
}
}
}
private static void printMenu() {
System.out.println("Welcome to Hess Burgers");
System.out.println("1- Cheeseburger.............$7");
System.out.println("2- Barbeque Burger..........$8");
System.out.println("3- Southwestern Burger......$9");
System.out.println("4- Bacon Cheeseburger.......$10");
System.out.println("5- Double Stack Burger......$11");
System.out.println("");
System.out.print("Please enter your order selection:");
}
}
I pulled the menu printing to a separate method, and re-used scanner a as well as re-using the orderString. The while loop checks a completedOrder boolean flag, so that it can be used to do completion tasks prior to exiting the order loop if need be.
import java.util.Scanner;
public class FibonacciCode {
public static void main(String[] args) {
System.out.println("Enter a number");
int count, number0 = 0, number1 = 1, loop = 0;
Scanner userInput = new Scanner(System.in);
count = userInput.nextInt();
while(loop > count)
{
System.out.print(number0 + ", ");
int sum = number0 + number1;
number0 = number1;
number1 = sum;
loop++;
}
}
}
A while loop does whatever is in the block as long as the condition is true, in your case, you are simply repeating order = b.nextInt() until something other than 'y' is given as input
while (continuePlay= b.nextLine().equalsIgnoreCase ("y")) {
order = b.nextInt(); // This is inside the block
}
you should use a do while loop instead, like so:
do{
System.out.println("Welcome to Hess Burgers");
System.out.println("1- Cheeseburger.............$7");
System.out.println("2- Barbeque Burger..........$8");
System.out.println("3- Southwestern Burger......$9");
System.out.println("4- Bacon Cheeseburger.......$10");
System.out.println("5- Double Stack Burger......$11");
System.out.println(" ");
System.out.print("Please enter your order selection:");
Scanner a = new Scanner(System.in);
int order = a.nextInt();
int total = 0;
boolean continuePlay = true;
if (order == 1 ) {
} else if (order == 2) {
} else if (order == 3) {
} else if (order == 4) {
} else if (order == 5) {
}
Scanner b = new Scanner(System.in);
System.out.println("Would you like to order more? Press 'y' to continue or 'n' to finish order.");
} while (continuePlay= b.nextLine().equalsIgnoreCase ("y"));
Also I'd recommend reading some basic programming books or tutorials instead of going directly to Stack Overflow.

InputMismatchException for guess number

I am doing a guessing game where in I can input 1-100 but I am having a trouble in only accepting numbers if I typed a letter when I first run the program it will give me error and execute the program instantly image herebut if ityped number after I start the program and type letter next it give me a wrong message it should only display message saying "invalid input".image here Any suggestion thanks.
package m1;
import java.util.InputMismatchException;
import java.util.Scanner;
public class M1{
public static void main(String[] args) {
Scanner Scanner = new Scanner(System.in);
int between = 100;
int secretNumber = (int)(Math.random()*between);
int inputNum = 0;
int guesses = 0;
System.out.println("Please enter your guess: ");
inputNum = Scanner.nextInt();
guesses++;
while (inputNum != secretNumber) {
try {
// number too high or too low
if (inputNum > 100 || inputNum < 1) {
System.out.println("Out of Range!");
System.out.println("Enter a guess between 1 and " + between + ".");
inputNum = Scanner.nextInt();
}
// less than secretNumber
if (inputNum < secretNumber) {
System.out.println("Too Low...Try Again!");
inputNum = Scanner.nextInt();
guesses++;
}
// greater than secretNumber
if (inputNum > secretNumber) {
System.out.println("Too High...Try Again!");
inputNum = Scanner.nextInt();
guesses++;
}
}
catch(InputMismatchException e){
System.out.println("Invalid Input");
Scanner.next();
}
}
System.out.println("\nWell done! The secret number was " + secretNumber + "." + "\nYou took " + guesses + " guesses.");
}
}
Generally, name variable names in java using camelCase in most cases.
You don't actually need to catch any exception in your case as you can simply do scanner.next() if scanner.hasNextInt() is false. Prompting the user to enter specifically a number this time.
Try the below code:
import java.util.Scanner;
import java.util.concurrent.ThreadLocalRandom;
class Main {
private static final String GUESS_PROMPT_PATTERN = "Please enter a guess between %d and %d inclusive: ";
private static final String WIN_PROMPT_PATTERN = "Well done! The secret number was %d. You took %d guesses.\n";
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int minimumGuess = 1, maximumGuess = 100;
int secretNumber = ThreadLocalRandom.current().nextInt(minimumGuess, maximumGuess + 1);
int guesses = 0;
String guessPrompt = String.format(GUESS_PROMPT_PATTERN, minimumGuess, maximumGuess);
System.out.println("Lec's Guessing Game");
System.out.println("====================");
System.out.print(guessPrompt);
while (scanner.hasNext()) {
if (scanner.hasNextInt()) {
guesses++;
int inputNum = scanner.nextInt();
if (inputNum == secretNumber) {
break;
}
// Input number too high or too low.
if (inputNum > maximumGuess || inputNum < minimumGuess) {
System.out.println("Out of Range!");
scanner.nextLine();
System.out.print(guessPrompt);
}
// Input number was less than the secret number.
else if (inputNum < secretNumber) {
System.out.println("Too Low... Try Again!");
System.out.print(guessPrompt);
}
// Input number was greater than the secret number.
else {
System.out.println("Too High... Try Again!");
System.out.print(guessPrompt);
}
} else {
System.out.print("ERROR: Invalid Input");
System.out.print("Please enter a number: ");
scanner.next();
}
}
System.out.printf(WIN_PROMPT_PATTERN, secretNumber, guesses);
}
}

Guessing game play again trouble

Ok so I've tried one method but it kept showing "Do you want to play again" every time i entered a number for some reason. Here is what I have so far. What else could i do to so that only after the user guesses the correct answer it asks if he/she wants to play again?
import java.util.Random;
import java.util.Scanner;
public class GuessNumber {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
Random rand = new Random();
int number = rand.nextInt(100) + 1;
int guess;
System.out.println("Guess the number between 1 and 100\n");
guess = scan.nextInt();
while (true) {
if(guess < number)
System.out.println("Higher!");
else if(guess > number)
System.out.println("Lower!");
else if (guess == number){
System.out.println("Correct!");
}
guess = scan.nextInt();
}
}
}
Try out this
class GuessNumber {
static Random rand = new Random();
static Scanner scan = new Scanner(System.in);
static int number;
public static void main(String[] args) {
playGame();
}
public static void playGame() {
number = rand.nextInt(100) + 1;
System.out.println("Guess the number between 1 and 100");
while (true) {
int guess = scan.nextInt();
if (guess < number) {
System.out.println("Higher!");
} else if (guess > number) {
System.out.println("Lower!");
} else if (guess == number) {
System.out.println("Correct!");
System.out.println("Do you like to play again?[1 for Yes/0 for No]");
int val = scan2.next();
if (val == 1)
playGame();
else
break;
}
}
}
}
or rather than using same scanner you can use another scanner and get string input as follows
else if (guess == number) {
System.out.println("Correct!");
Scanner scan2 = new Scanner(System.in);
System.out.println("Do you like to play again?[Y/N]");
String val = scan2.next();
if (val.equalsIgnoreCase("Y"))
playGame();
else
break;
}
You need to exit the while when correct.
To do so, after the line:
System.out.println("Correct!");
Add another line like this:
break;
Mostly out of fun, I implemented a game that fits the description of what you were trying to do. The code is not the cleanest / most efficient, but it definitely works!
Take a look at it and see if you can figure out your problem.
import java.util.Random;
import java.util.Scanner;
public class GuessingGame {
public static void main(String[] args) {
System.out.println("Guess the number between 1 and 100");
playGuessingGame();
while (true) {
System.out
.println("Do you want to play again? Type y / n and hit enter");
Scanner scan = new Scanner(System.in);
String playAgain = scan.next();
if (playAgain.charAt(0) == 'y') {
System.out.println("Okay, I picked a new number. Good luck!");
playGuessingGame();
} else {
System.out.println("Thanks for playing!");
break;
}
}
}
public static void playGuessingGame() {
Scanner scan = new Scanner(System.in);
Random rand = new Random();
int guess;
int number = rand.nextInt(100) + 1;
guess = scan.nextInt();
while (guess != number) {
if (guess < number)
System.out.println("Higher!");
else if (guess > number)
System.out.println("Lower!");
else if (guess == number) {
System.out.println("Correct!");
}
guess = scan.nextInt();
}
}
}

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