I'm in a Beginner Java class and I'm confused about using additional methods and using them in another. I think that I have most of my assignment done but I just need help to create the methods. One is to generate the question and the other one is to display the message.
I know that in order to call a method
public static test(num1,num2,num3)
but in my code, how do I make it so that I call the method and still make it loop correctly?
In the assignment instructions that was given to me, In order to do that, I have to write a method named
public static in generateQuestion()
and
public static void displayMessage(boolean isCorrect)
This is my code:
//For Random Generator
import java.util.Random;
//Uses a class Scanner
import java.util.Scanner;
public class Assign6
{
public static void main(String[] args)
{
//Scanner to Obtain Input from CW
Scanner input = new Scanner(System.in);
//Generate Random Number for Quiz
Random randomNumbers = new Random();
int number1 = 0;
int number2 = 0;
int answer = 0;
//Rolls number from 1-9
number1 = randomNumbers.nextInt(9);
number2 = randomNumbers.nextInt(9);
//Question prompt
System.out.println("How much is " +number1+ " times " +number2+ "? ");
answer = input.nextInt();
//If Else While Statements
if(answer == (number1*number2))
{
System.out.println("Good job! You got it right!");
}
else
{
while (answer !=(number1*number2))
{
System.out.println("You got it wrong, try again!");
answer = input.nextInt();
}
}
}
}
You are going to have two methods
public static void generateQuestion()
Which is going to hold the code to generate the random values and output it. It will return void because all it's doing is printing out.
Next you will have
public static void displayMessage(boolean isCorrect)
which will be called if if(answer == (number1*number2)) is true with true as the parameter. Otherwise it will still be called, but the parameter passed in will be false. This method will determine if isCorrect is true or false, and output the appropriate message.
If I got it right, I have a solution that might be a little stupid but will work for your assignment.
If you make generateQuestion that makes two random ints, prints the question and returns their multiple (answer).
And displayMessgae that prints "Good job! You got it right!" if isCorrect is true and "You got it wrong, try again!" else,
you can call generateQuestion, then get an answer (in main), and loop until answer is correct (according to return value of generateQuestion).
Every time you get a new answer (in loop), call displayMessgae(false).
After the loop ended call displayMessgae(true)
This is my working code for this:
//For Random Generator
import java.util.Random;
//Uses a class Scanner
import java.util.Scanner;
public class Assign6
{
public static int generateQuestion()
{
Random r = new Random();
int x = r.nextInt(9), y = x = r.nextInt(9);
System.out.println("How much is " + x + " times " + y + "? ");
return x * y;
}
public static void displayMessage(boolean isCorrect)
{
if (isCorrect)
System.out.println("Good job! You got it right!");
else
System.out.println("You got it wrong, try again!");
}
public static void main(String[] args)
{
//Scanner to Obtain Input from CW
Scanner input = new Scanner(System.in);
int rightAnswer = 0;
rightAnswer = generateQuestion();
while (input.nextInt() != rightAnswer)
displayMessage(false);
displayMessage(true);
}
}
If I understand your question correctly, It's simply a matter of separating the functionality that prints a question and displays the answer into separate methods. See my edited version of your code below
public class Assign6
{
public static void main(String[] args)
{
// Scanner to Obtain Input from CW
Scanner input = new Scanner(System.in);
// Generate Random Number for Quiz
Random randomNumbers = new Random();
int number1 = 0;
int number2 = 0;
int answer = 0;
// Rolls number from 1-9
number1 = randomNumbers.nextInt(9);
number2 = randomNumbers.nextInt(9);
displayQuestion("How much is " + number1 + " times " + number2 + "?");
answer = input.nextInt();
// If Else While Statements
if (answer == (number1 * number2))
{
displayMessage(Boolean.TRUE);
}
else
{
while (answer != (number1 * number2))
{
displayMessage(Boolean.FALSE);
answer = input.nextInt();
}
}
}
public static void displayQuestion(String q)
{
System.out.println(q);
}
public static void displayMessage(Boolean isCorrect)
{
if (isCorrect)
{
System.out.println("Good job! You got it right!");
}
else
{
System.out.println("You got it wrong, try again!");
}
}
}
Related
I am trying to build a math Calculator in Java but I am having problems with it, I want to build it with methods and not just int.
I am having problems with how to print the return value (rishon+sheni) and also how to check if the in.nextLine() that the console wrote equal to plus like that:
package mehadash;
import java.util.Scanner;
public class lilmod {
public static void main(String[] args)
{
Scanner in = new Scanner(System.in);
String plus = null;
String minus = null;
String math;
int sum = 0;
System.out.println("What kind of math you want to do?");
math = in.nextLine();
if(math = plus)
{
System.out.println("Enter the two numbers you would like to check");
SumNumbers(in.nextInt(),in.nextInt());
System.out.println("The answer is :" +SumNumbers());
}
minusNumbers(in.nextInt(),in.nextInt());
}
public static int SumNumbers(int rishon , int sheni)
{
return rishon + sheni;
}
public static int minusNumbers(int rishon , int sheni)
{
return rishon - sheni;
}
}
You can always just define more variables.
int numberA = in.nextInt();
int numberB = in.nextInt();
int result = SumNumbers(numberA, numberB);
System.out.println("The result: " + result);
how to print the return value (rishon+sheni)
Try this way:
System.out.println("The answer is :" +SumNumbers(in.nextInt(),in.nextInt()));
instead of
SumNumbers(in.nextInt(),in.nextInt());
System.out.println("The answer is :" +SumNumbers());
also how to check if the in.nextLine(); that the console wrote equal
to plus
Try
if(math.equals("+"))
instead of
if(math = plus)
I know it's very basic java but I am trying to learn. Can someone help me to understand my errors and what should I do to solve it?
package com.company;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
int teamA = 0;
int teamB = 0;
//asks for the team selection
System.out.println("Would you like to be in Team A or Tema B? Write A for team A and B for team B");
Scanner input = new Scanner(System.in);
int result = input.nextInt();
public String scoreBoard() {
String displayScoreBoard = "No Score";
if (result.toString == "A" || result.toString == "a"){
teamA++;
displayScoreBoard = "Score of TeamX is" + teamA;
} else if (result.toString == "B" || result.toString == "b"){
teamB++;
displayScoreBoard = "Score of TeamY is" + teamB;
} System.out.println(displayScoreBoard.toString);
}
// write your code here
}
}
You made several mistakes. For example you wrote a function within a function. You better don't do that. Just look at my code. If you have any questions, just ask ;)
UPDATE: Due to the comments that there should be a loop, I've adapted the code.
import java.util.Scanner;
public class Main{
public static void main(String[] args) {
int teamA = 0;
int teamB = 0;
//asks for the team selection
while(true) {
System.out.println("Would you like to be in Team A or Tema B? Write A for team A and B for team B. Type anything else to quit.");
Scanner input = new Scanner(System.in);
String result = input.next();
if (result.toUpperCase().equals("A")) {
System.out.println("Score of TeamX is" + ++teamA);
} else if (result.toUpperCase().equals("B")) {
System.out.println("Score of TeamY is" + ++teamB);
}
else {
break;
}
}
}
}
I'm trying to make a program which asks the user a particular bird then how many of them they had seen at that point. If the use at any point enters the word 'END' then the system should print out the most seen bird and the number seen. However, when running my program if I enter 'END' at random points it instead returns that the most seen was END with 0 seen. I can't figure out how to make it work. I've tried different methods but it's just not working properly. Also, I've set the maximum array limit to 10 possitions but it continues after 10 and if i enter a value the system crashes. Have I written the limit part properly? Or am I missing something important?
import java.util.Scanner;
public class testing
{
public static void main (String[] param)
{
birdInput();
most();
System.exit(0);
}
public static void birdInput()
{
int i = 0;
String birdInput;
int numberInput;
Scanner scanner = new Scanner(System.in);
int maxVal = Integer.MIN_VALUE;
int maxValIndex = -1;
while (true)
{
System.out.println("What bird did you see?");
birdInput = scanner.nextLine();
if (birdInput.equals("END"))
{
System.out.print("\nWell....I guess thanks for using this program?\n");
System.exit(0);
}
else
{
String[] birds = new String[10];
int[] numbers = new int[10];
birds[i] = scanner.nextLine();
System.out.println("How many did you see?");
numbers[i] = scanner.nextInt();
i++;
if (birds[i].equals("END"))
{
maxVal = numbers[i];
maxValIndex = i;
System.out.print("\nThe most common bird that you saw was the " + birds[maxValIndex] + " with " + maxVal + " being seen in total\n");
System.exit(0);
}
}
}
}
public static void most()
{
System.out.println("fdff");
}
}
This is my edit of Till Hemmerich's answer to my issue. I tried to remove the global variables and so combine the entire code into 1 method. However, I'm still having some issues. Been working at it but really confused.
import java.util.Scanner;
public class birds2
{
public static void main(String[] param)
{
birdInput();
System.exit(0);
}
public static void birdInput()
{
Scanner scanner = new Scanner(System.in);
String[] birds = new String[99999999];
int[] numbers = new int[99999999];
int i = 0;
int maxIndex;
while (i <= birds.length)
{
System.out.println("What bird did you see?");
birds[i] = scanner.nextLine();
System.out.println("How many did you see?");
numbers[i] = scanner.nextInt();
i++;
}
int newnumber = numbers[i];
if ((newnumber > numbers.length))
{
maxIndex = i;
i++;
}
if (birds[i].toUpperCase().equals("END"))
{
System.out.print("\nWell....I guess thanks for using this program?\n");
System.out.print("\nThe most common bird that you saw was the " + birds[maxIndex] + " with " + numbers[maxIndex] + " being seen in total\n");
System.exit(0);
}
}
}
You're re-declaring the birds and numbers arrays in each iteration of the loop. They should be declared and initialized only once, before the loop.
I changed a lot so im going to explain my changes here in total.
First of all i had to move the Array Definition out of your while-loop as >mentioned above, since other wise you would override these Arrays every time.
I also made them globally accessible to work with them in other methods.
public static int maxIndex;
public static String[] birds = new String[10];
public static int[] numbers = new int[10];
in general I re structured the whole code a little bit to make it more readable and a little bit more object-orientated.
For example I created an method called inputCheck() which returns our input as a String and check if it equals END so you do not have to write your logic for this twice. (it also considers writing end lower or Uppercased by just Upper our input before checking it"if (input.toUpperCase().equals("END"))")
static String inputCheck() {
Scanner scanner = new Scanner(System.in);
String input = scanner.nextLine();
if (input.toUpperCase().equals("END")) {
end();
}
return input;
}
this method can now be called every time you need an input like this:
birds[i] = inputCheck();
but you need to be carefull if you want to get an integer out of it you first have to parse it like this:Integer.parseInt(inputCheck())
after that I wrote a method to search for the biggest Value in your numbers Array and getting its index:
public static int getMaxIndex(int[] numbers) {
for (int i = 0; i < numbers.length; i++) {
int newnumber = numbers[i];
if ((newnumber > numbers.length)) {
maxIndex = i;
}
}
return maxIndex;
}
it takes an int array as parameter and returns the index of the highest element in there as an Integer. Called like this:maxIndex = getMaxIndex(numbers);
Then after that I rewrote your end method. It now just calles our getMaxIndex method and prints some output to the console.
public static void end() {
maxIndex = getMaxIndex(numbers);
System.out.print("\nWell....I guess thanks for using this program?\n");
System.out.print("\nThe most common bird that you saw was the " + birds[maxIndex] + " with " + numbers[maxIndex] + " being seen in total\n");
System.exit(0);
}
to fix your last problem (crashing after more then 10 inputs)I changed your while-loop. Since your array only has 10 places to put things it crashes if you try to put information in place number 11. it not looks like this:while (i <= birds.length) instead of while (true) this way the max loops it can take is the amout of places Array birds has and it wont crash anymore.
public static void birdInput() {
int i = 0;
while (i <= birds.length) {
System.out.println("What bird did you see?");
birds[i] = inputCheck();
System.out.println("How many did you see?");
numbers[i] = Integer.parseInt(inputCheck()); //you should check here if its actuall a number otherwiese your programm will crash
i++;
}
}
Here is the whole code in total:
import java.util.Scanner;
/**
*
* #author E0268617
*/
public class JavaApplication1 {
public static int maxIndex;
public static String[] birds = new String[10];
public static int[] numbers = new int[10];
public static void main(String[] param) {
birdInput();
most();
System.exit(0);
}
public static void birdInput() {
int i = 0;
while (i <= birds.length) {
System.out.println("What bird did you see?");
birds[i] = inputCheck();
System.out.println("How many did you see?");
numbers[i] = Integer.parseInt(inputCheck()); //you should check here if its actuall a number otherwiese your programm will crash
i++;
}
}
static String inputCheck() {
Scanner scanner = new Scanner(System.in);
String input = scanner.nextLine();
if (input.toUpperCase().equals("END")) {
end();
}
return input;
}
public static int getMaxIndex(int[] numbers) {
for (int i = 0; i < numbers.length; i++) {
int newnumber = numbers[i];
if ((newnumber > numbers.length)) {
maxIndex = i;
}
}
return maxIndex;
}
public static void end() {
maxIndex = getMaxIndex(numbers);
System.out.print("\nWell....I guess thanks for using this program?\n");
System.out.print("\nThe most common bird that you saw was the " + birds[maxIndex] + " with " + numbers[maxIndex] + " being seen in total\n");
System.exit(0);
}
public static void most() {
System.out.println("fdff");
}
}
I hope you understand where the Problems had been hidden if you have any Questions hit me up.
I'm creating a high/low guessing game as part of a study assignment, and the part im stuck at is getting the amount of guesses returned to the main method. We have specifically been told that the main method has to print the number of guesses, while the method "playGame" actually does the playing.
There's more to the code, a method called giveReponse that checks if the number is correct or too high/low, but it works as intended. I get "Cannot find symbol" when trying to print how many guesses it took to complete the game.
If it wasn't so important to print it in the main method I'd print the amount in the method playGame, but thats a no-go. What am I doing wrong?
The code looks like this:
public class HiLo {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("Welcome to classic guessing game of high/low!");
String difficulty = scan.next();
if (difficulty.equals("easy")) {
playGame(10);
} else if (difficulty.equals("medium")) {
playGame(100);
} else if (difficulty.equals("hard")) {
playGame(1000);
}
System.out.println("You won in" + guesses + "attempts.");
}//EndsMain
public static int playGame(int maxNumber) {
Scanner scan = new Scanner(System.in);
int rannr = (int)(Math.random() * maxNumber) +1;
int answer = rannr;
int guess = 0;
int guesses = 0;
System.out.println("Game is starting...");
do {
guess = scan.nextInt();
guesses ++;
giveResponse(answer, guess);
if (answer == guess) {
break;
}
} while (answer != guess);
return guesses;
} //Ends playGame
Your method playGame( ) is returning a value but since is not assigned to no variable, those returns are getting lost...
additional to that it looks like the code is not complete:
this statement is not going to let you compile:
System.out.println("You won in" + guesses + "attempts.");
because the only guesses variable I see in there is scoped in the playGame method....
do instead something like:
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("Welcome to classic guessing game of high/low!");
int guesses = 0;
String difficulty = scan.next();
if (difficulty.equals("easy")) {
guesses = playGame(10);
} else if (difficulty.equals("medium")) {
guesses = playGame(100);
} else if (difficulty.equals("hard")) {
guesses = playGame(1000);
}
The problem is at:
System.out.println("You won in" + guesses + "attempts.");
Since the variable guesses is not defined in the main method, the compiler doesn't know what you are referencing to with that symbol.
But since playGame() returns the number of guesses, I'd recommend something like this:
if (difficulty.equals("easy")) {
System.out.println("You won in" +playGame(10)+ "attempts.");
} else if (difficulty.equals("medium")) {
System.out.println("You won in" +playGame(100)+ "attempts.");
} else if (difficulty.equals("hard")) {
System.out.println("You won in" +playGame(1000)+ "attempts.");
}
Here's a solution that shows how easy it would be to restrict guesses. Not much extra effort or thought:
package games;
import java.util.Random;
import java.util.Scanner;
/**
* HiLo guessing game
* Created by Michael
* Creation date 4/9/2016.
* #link https://stackoverflow.com/questions/36522303/java-creating-hi-low-game-using-multiple-methods-stuck-at-returning-no-of-gu
*/
public class HiLo {
public static void main(String [] args) {
int maxValue = (args.length > 0) ? Integer.parseInt(args[0]) : 100;
int maxGuesses = (args.length > 1) ? Integer.parseInt(args[1]) : 5;
Scanner scanner = new Scanner(System.in);
String answer = "Y";
do {
play(scanner, maxValue, maxGuesses);
System.out.println("Play again? [Y/N]: ");
answer = scanner.next();
System.out.println(String.format("You answered %s; let's play again!", answer));
} while ("Y".equalsIgnoreCase(answer));
}
private static void play(Scanner scanner, int maxValue, int maxGuesses) {
int value = new Random().nextInt(maxValue) + 1;
int numGuesses = 0;
boolean match = false;
do {
System.out.println(String.format("Guess a value between 1 and %d: ", maxValue));
int guess = Integer.parseInt(scanner.next());
if (guess < value) {
System.out.println(String.format("Too low; guess again. (%d guesses left)", (maxGuesses-numGuesses-1)));
} else if (guess > value) {
System.out.println(String.format("Too high; guess again (%d guesses left)", (maxGuesses-numGuesses-1)));
} else {
match = true;
System.out.println(String.format("You got it right in %d guesses! ", numGuesses+1));
break;
}
} while (!match && ++numGuesses < maxGuesses);
if (!match) {
System.out.println(String.format("The correct answer was %d; you're only allowed %d guesses. Better luck next time!", value, maxGuesses));
}
}
}
I'm trying to make a quiz type game and for some reason when I add the if statement below it executes the ask method twice. You will get asked the question twice before it returns whether it is correct or not.
import java.util.Scanner;
public class QuizGame
{
private int correct;
private int wrong;
private Scanner inputScan;
private Quiz customQuiz;
public QuizGame()
{
correct=0;
wrong=0;
inputScan = new Scanner(System.in);
}
private void startQuiz()
{
System.out.println("Use custom upper limit? (y/n) ");
String custom = inputScan.next();
if(custom.equalsIgnoreCase("y"))
{
System.out.println("What do you want to be your upper limit?");
int limit = inputScan.nextInt();
customQuiz = new Quiz(limit);
customQuiz.ask();
if(customQuiz.ask())
{
correct +=1;
System.out.println("Correct!");
}
else
{
wrong+=1;
System.out.println("Wrong!");
}
}
}
public static void main(String[] args)
{
QuizGame quiz1 = new QuizGame();
quiz1.startQuiz();
}
}
other class that asks the questions:
import java.util.Random;
import java.util.Scanner;
public class Quiz
{
private Random rGen;
private int num1;
private int num2;
private Scanner getInput;
private int answer;
public Quiz(int n1)
{
rGen = new Random();
num1 = rGen.nextInt(n1);
num2 = rGen.nextInt(n1);
getInput = new Scanner(System.in);
}
public boolean ask()
{
int answer = num1 * num2;
System.out.println("What is " + num1 + " x " + num2);
int userAnswer = getInput.nextInt();
return answer == userAnswer;
}
}
I isolated the problem and it definitely seems to be the if statement: if(customGame.ask()) {} in the driver class, but I don't see why. It's not like if(customGame.ask()) calls the ask method again, it just tests if it returns true? I've also tried with just if(customGame.ask() == true) and still nothing.
Well, you are calling customQuiz.ask() twice :
customQuiz.ask();
if (customQuiz.ask ())
{
correct += 1;
System.out.println ("Correct!");
}
Simply call it just once :
if (customQuiz.ask ())
{
correct +=1;
System.out.println ("Correct!");
}
Or (as suggested by #RobertHarvey) you can put the result of the method in a variable and use it later :
boolean correct = customQuiz.ask ();
if (correct)
{
correct += 1;
System.out.println ("Correct!");
}