Develop Reference

How to output an error message to the user and repeat to allow them to enter the word again if the user enters more than one word

Please Help!
If the user enters more than one word, output an error message to the user and repeat to allow them to enter the word again.
This is the code I have:
public void computeLetters(){
for(int i = 0; i < term.length()-1; i++){
if(term.charAt(i)==' ' && term.charAt(i+1)!=' ')
numberWords = 1;
}
for(int numberWords = 1; numberWords > 0;){
JOptionPane.showMessageDialog(null,"Please try again");
JOptionPane.showInputDialog(null,"Enter a word");
numberWords = 0;
}
for(int numberWords = 0; numberWords < 1;){
for(int j = 0; j < term.length()-1; j++){
numberLetters++;
}
}
}

A loop should work...
public void computeLetters()
{
while (true) {
// Get user input
String term = JOptionPane.showInputDialog("Enter a word");
if (null == term) return;
// Check if more than 1 word (has a space)
String [] words = term.split(" ");
// Single word?
if (words.length == 1) {
// Get letter count
int numberLetters = words[0].length();
// Do something else here???
// Done
return;
}
// Show error message
JOptionPane.showMessageDialog(null, "Please try again");
// And try again...
}
}
Edit based on comment using only if statements, loops or chars & strings (and ints).
public void computeLetters()
{
int numberLetters = 0;
while (numberLetters == 0) {
// Get user input
String term = JOptionPane.showInputDialog("Enter a word");
if (null != term) {
// Check if more than 1 word (has a space)
for (int i = 0; i < term.length(); i++) {
if (' ' == term.charAt(i)) {
numberLetters = 0;
break;
}
numberLetters += 1;
}
}
if (numberLetters == 0) {
JOptionPane.showMessageDialog(null, "Please try again");
}
}
// Do something with numberLetters here....
}

public void computeLetters(){
numberWords = term.trim().split("\\s+").length;
if(numberWords > 0 ){
JOptionPane.showMessageDialog(null,"Please try again");
term = JOptionPane.showInputDialog(null,"Enter a word");
computeLetters();
}
}
Number of words check, changed to a single line of code.
Next, the for loop in your code can be replaced by a simple 'if' as shown.
Then the next loop would have been an infinite loop. Just calling the function again after getting value from the user will do!

If this method is trying to get a single word from the user, validate it is one word, then count the number of letters in that word. This is how I would do it.
public int computeLetters()
{
String myWord = JOptionPane.showInputDialog("enter a single word.");
while(myWord.contains(" "))
{
JOptionPane.showMessageDialog("Cannot be more than one word.");
myWord = JOptionPane.showInputDialog("enter a single word.");
}
return myWord.toCharArray().length;
}

How to break from a loop after finding a word

I am trying to create a Hangman and I have 2 problems.
1) The first problem is when the user finds the word, the loop does not stop.
2) I have a variable attempts which allows to know the number of attempts. Even if the user finds the letter, the number of attempts decrease.
The word to find is no
Here is a demonstration:
1) I enter the letter n
You have 5 attempts.
--
Enter your letter : n
2) I enter the letter o
The letter is good.
You have 4 attempts.
n-
Enter your letter : o
3) Normally the loop should stop.
The letter is good.
You have 3 attempts.
no
Enter your letter :
If you have an idea thank you in advance.
Scanner input = new Scanner(System.in);
char letter = 0;
String[] words = {/*"yes",*/ "no"};
String word_random = words[(int) (Math.random() * words.length)];
boolean[] word_found = new boolean[word_random.length()];
int attempts = 5;
while(attempts > 0){
System.out.println("You have " + attempts + " attempts.");
for(int i=0; i<word_random.length(); i++) {
if ( word_found[i] ) {
System.out.print(word_random.charAt(i));
}
else {
System.out.print('-');
}
}
System.out.println("");
System.out.print("Enter your letter : ");
letter = input.next().charAt(0);
for(int i=0; i<word_random.length();i++){
if(word_random.charAt(i) == letter){
System.out.println("The letter is good. ");
word_found[i] = true;
}
}
attempts--;
}
}
}

You are just missing a checking loop or method. Check the solution below.
Scanner input = new Scanner(System.in);
char letter = 0;
String[] words = {/*"yes",*/ "no"};
String word_random = words[(int) (Math.random() * words.length)];
boolean[] word_found = new boolean[word_random.length()];
int attempts = 5;
while(attempts > 0){
System.out.println("You have " + attempts + " attempts.");
for(int i=0; i<word_random.length(); i++) {
if ( word_found[i] ) {
System.out.print(word_random.charAt(i));
}
else {
System.out.print('-');
}
}
System.out.println("");
System.out.print("Enter your letter : ");
letter = input.next().charAt(0);
for(int i=0; i<word_random.length();i++){
if(word_random.charAt(i) == letter){
System.out.println("The letter is good. ");
word_found[i] = true;
}
}
boolean done = true;
for(boolean b : word_found)
done = done && b;
if(done) break;
else attempts--;
}

I will follow to your solution, not suggest a better one.
Ad 1. Add a check if the array word found contains only true after your first for cycle and if there are only true values in the array, print "you won" and set attempts to 0
Ad 2. Move attempts-- to the else case of your first for cycle OR add attempts++ in the true case of your first for cycle

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
char letter = 0;
String[] words = { /* "yes", */ "no" };
String word_random = words[(int) (Math.random() * words.length)];
boolean[] word_found = new boolean[word_random.length()];
int attempts = 5;
while (attempts > 0) {
System.out.println("You have " + attempts + " attempts.");
for (int i = 0; i < word_random.length(); i++) {
if (word_found[i]) {
System.out.print(word_random.charAt(i));
} else {
System.out.print('-');
}
}
System.out.println("");
System.out.print("Enter your letter : ");
letter = input.next().charAt(0);
boolean match = false;
for (int i = 0; i < word_random.length(); i++) {
if (word_random.charAt(i) == letter) {
System.out.println("The letter is good. ");
word_found[i] = true;
match = true;
if (i == word_found.length - 1) {
System.out.println("THE END: attempts: " + attempts);
return;
}
}
}
if (!match) {
attempts--;
}
}
System.out.println("THE END");
}
I suggest you to modify the last part of your code like I did, and it should work.

How to get correct output for Pig Latin translator using JAVA

I am coding a JAVA application that translates english to pig latin. My application runs with no actual errors but the output is automatic and incorrect. This application will continue to run if the user selects "y".
Can you all see where my error lies?
Thank you.
CODE:
import java.util.Scanner;
public class PigLatin2 {
public static void main(String[] args) {
// create a Scanner object
Scanner sc = new Scanner(System.in);
// Run through the loop of calculations while user choice is equal to "y" or "Y"
String choice = "y";
while (choice.equalsIgnoreCase("y")) {
// get the input from the user
System.out.println("Enter a line to be translated");
System.out.println();
//Get String entered
String userInput = sc.toString();
//Line break
System.out.println();
String[] words = userInput.split(" ");
String output = "";
for(int i = 0; i < words.length; i++) {
String pigLatin = translated(words[i]);
output += pigLatin + " ";
}
System.out.println(output);
//Scan next line
sc.nextLine();
//line break
System.out.println();
// Ask use they want to continue
System.out.print("Continue? (y/n): ");
//Users choice
choice = sc.nextLine();
System.out.println();
}//END WHILE LOOP
//Close scanner object
sc.close();
}//END MAIN METHOD
private static String translated(String words) {
String lowerCase = words.toLowerCase();
int firstVowel = -1;
char ch;
// This for loop finds the index of the first vowel in the word
for (int i = 0; i < lowerCase.length(); i++) {
ch = lowerCase.charAt(i);
if (startsWithVowel(ch)) {
firstVowel = i;
break;
}
}
if (firstVowel == 0) {
return lowerCase + "way";
}else {
String one = lowerCase.substring(firstVowel);
String two = lowerCase.substring(0, firstVowel);
return one + two + "ay";
}
}
public static Boolean startsWithVowel(char ch) {
if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' || ch == 'y') {
return true;
}
return false;
}
}
This is the output I get automatically:
ava.util.scanner[delimiters=\p{javawhitespace}+][position=0][matchjay alid=false][needvay input=false][sourceway osed=false][skipped=false][groupclay eparator=\,][decimalsay eparator=.][positivesay efix=][negativepray efix=\q-\e][positivepray uffix=][negativesay uffix=][nansay ing=\qnan\e][infinitystray ing=\q?\e]stray

Hangman, exits the game without getting the user response (loop)

I got a couple issues with my code. I know it is not the best looking design/coding but I don't claim to be a good programmer yet. I have to other classes does their work correctly. Dictionary class which contains a word list and HangmanAnimation class which draws the hangman onto console.
Now, I want my game to ask to player if he/she wants to play again after the game finished. Actually, it does asking if player wants to play again but exits the game before the player can type anything.
I would appreciate any other suggestions aswell. Thanks in advance! You guys really rock! :)
public class HangmanGame {
public static void main(String[] args) {
HangmanUI ui = new HangmanUI();
ui.initialize();
String input = "";
if(ui.newGame(input).equalsIgnoreCase("yes"))
main(null);
}
}
public class HangmanUI {
private final Dictionary d = new Dictionary();
private final HangmanAnimation ha = new HangmanAnimation();
private String wordInProgress = d.getWordInProgress();
Scanner sc = new Scanner(System.in);
private int maxTries = 5;
String word;
public void initialize() {
int easyWords = 1;
int hardWords = 2;
System.out.println("Welcome to Hangman game.");
System.out.println("=========================");
System.out.println("Rules: You need to find the given word in 5 tries.");
System.out.println("You will continue guessing letters until you can either");
System.out.println("solve the word or all five body parts are on the gallows.");
System.out.println("In that case you will lose the game. Try not to enter");
System.out.println("same letter more than once. Those are counts too.");
System.out.println();
System.out.println("Choose your game level or Quit:");
System.out.println("1) Easy");
System.out.println("2) Hard");
System.out.println("3) Quit");
try {
int playersChoice = sc.nextInt();
switch (playersChoice) {
case 1:
d.wordList(easyWords);
break;
case 2:
d.wordList(hardWords);
break;
case 3:
System.out.println("Thank you for your time!");
System.exit(0);
default:
System.out.println("Invalid input. Try again!");
initialize();
}
word = d.pickRandomWord(d.getWordList());
hideWord(word);
while(maxTries > 0) {
if(wordInProgress.contains("-")) {
System.out.println(wordInProgress);
revealLetter(notifyGuess());
} else {
System.out.println("Good work! You found the word.");
}
}
} catch (InputMismatchException e) {
System.out.println("Invalid input. Use only digits!");
}
}
//TODO: Do not count same letter more than once & let player to know.
public char notifyGuess() {
ArrayList<Character> charSet = new ArrayList<>();
System.out.print("Please enter a letter: ");
char c = sc.next().charAt(0);
if(Character.isDigit(c)){
System.out.println("You can't use numbers. Please enter a letter.");
notifyGuess();
} else if(charSet.contains(c)) {
System.out.println("You already used '" + c + "' before.");
notifyGuess();
} else
charSet.add(c);
return c;
}
public void hideWord(String word) {
StringBuilder sb = new StringBuilder();
for(int i = 0; i < word.length(); i++) {
sb.append("-");
}
wordInProgress = sb.toString();
}
public void revealLetter(char c) {
try {
String temp = wordInProgress;
char[] charArray = wordInProgress.toCharArray();
for (int i = 0; i < word.length(); i++) {
if(c == word.charAt(i))
charArray[i] = word.charAt(i);
}
wordInProgress = new String(charArray);
if(temp.equals(wordInProgress)){
maxTries--;
ha.drawHanging(maxTries);
} else {
System.out.println("Good! There is '" + c + "' in the word.");
}
} catch (StringIndexOutOfBoundsException e) {
System.err.println("You have to enter a character!");
}
}
public String newGame(String input) {
System.out.println("Do you want to play again? (yes/no)");
input = sc.nextLine();
return input;
}
}

Try using this:
System.out.println("Do you want to play again? (yes/no)");
input = sc.next(); //<== here is the change
return input;

How to reject inputs that are non digit characters?

My professor assigned to write a prime number "finder". Where the number you input will display if it's a prime or even number, then display the next prime number. He wants us to give an error message when the wrong input is keyed in. I figured the negative integer portion is simple, but I cannot figure out the character input. Or if the character is not a digit. How would i block non numeric inputs?
Also, the system is supposed to exit at three CONSECUTIVE erroneous inputs. How would I reset the counter? The way i have written the program, if the user makes two errors but the next ones are acceptable, then make another error. (thus not being consecutive.) the program closes.
This is my first programing course so I'm not to savvy in it. Any help would be greatly appreciated.
Also, i have to use scanner, and the two methods.
/**
*
* #param n
* #return
*/
public static boolean isPrime(int n) {
for (int i = 2; i < n; i++) {
if (n % i == 0) {
return false;
}
}
return true;
}
public static int nextPrime(int n) {
n++;
isPrime(n);
while (isPrime(n) == false) {
n++;
isPrime(n);
}
int prime = n;
return prime;
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
int answer = 2;
int counter = 1;
boolean playAgain = false;
Scanner input = new Scanner(System.in);
Scanner reader = new Scanner(System.in);
Scanner in = new Scanner(System.in);
do {
//ask for input
System.out.print("\nEnter the integer value-> ");
//input answer
int n = input.nextInt();
{
//decide is negative
while ( n < 0){
//count counter
counter++;
//give error message
System.out.println("\nInvalid Input! Stike!");
//ask for input
System.out.print("\nEnter the integer value-> ");
//input answer
n = input.nextInt();
//decide is character
// if ( n != '.'){
//count counter
// counter++;
//give error message
// System.out.println("\nInvalid Input! Strike!");
// }
//decide if count three errors
if (counter == 3){
//display three errors message
System.out.println("Three Strikes! You're Out!");
//close program
System.exit(0);
}
}
//decide if prime
if (isPrime(n)) {
//display prime answer
System.out.println(n + " Is Prime");
//decide if even
} else {
//display even answer
System.out.println(n + " Is Even");
}
//counter input
n++;
//while input is false
while (isPrime(n) == false) {
n++;
}
//display next prime
System.out.println(n + " Next prime");
{
//ask if you want to continue
System.out.println("\nPlay Again?\n\nEnter 1)Yes or 2)No ");
//input answer
answer = in.nextInt();
//if answer is 1)yes
if (answer == 1) {
playAgain = true;
//display play again and next input
System.out.println("\nPlay Again!");
}
//if answer is no
if (answer == 2) {
playAgain = false;
System.out.println("\nGoodbye!");
//close program
System.exit(0);
}
}
}
} while (playAgain != false);
}
}

import java.util.Scanner;
public class SOQ5B
{
public static boolean isPrime(int n) {
for (int i = 2; i < n; i++) {
if (n % i == 0) {
return false;
}
}
return true;
}
public static int nextPrime(int n) {
n++;
isPrime(n);
while (isPrime(n) == false) {
n++;
isPrime(n);
}
int prime = n;
return prime;
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
int answer;
int counter = 0;
int n;
boolean playAgain = true;
boolean isNum;
boolean isNum2;
boolean continuePermitted = true;
Scanner input = new Scanner(System.in);
String s;
do {
//ask for input
System.out.print("\nEnter the integer value-> ");
s = input.nextLine();
isNum = true;
for(int i = 0; i < s.length(); i++)
{
if(!(s.charAt(i) >= '0' && s.charAt(i) <= '9'))
{
isNum = false;
}
}
if(isNum)
{
counter = 0;
n = Integer.parseInt(s);
//decide if prime
if (isPrime(n)) {
//display prime answer
System.out.println(n + " Is Prime");
//decide if even
}
else {
//display even answer
System.out.println(n + " Is Even");
}
//counter input
n++;
//while input is false
while (isPrime(n) == false) {
n++;
}
//display next prime
System.out.println(n + " Next prime");
do
{
continuePermitted = true;
//ask if you want to continue
System.out.println("\nPlay Again?\n\nEnter 1)Yes or 2)No ");
//input answer
s = input.nextLine();
isNum2 = true;
for(int i = 0; i < s.length(); i++)
{
if(!(s.charAt(i) >= '0' && s.charAt(i) <= '9'))
{
isNum2 = false;
}
}
if(isNum2)
{
answer = Integer.parseInt(s);
//if answer is 1)yes
if (answer == 1) {
playAgain = true;
//display play again and next input
System.out.println("\nPlay Again!");
}
//if answer is no
if (answer == 2) {
playAgain = false;
System.out.println("\nGoodbye!");
//close program
System.exit(0);
}
}
else
{
System.out.println("Incorrect response.");
continuePermitted = false;
//if answering the yes or no question incorrectly is part of the 3 strikes
//then uncomment the following lines of code
/*
counter++;
}
if(counter >= 3)
{
System.out.println("3 strikes you out");
System.exit(0);
*/
}
}while(!continuePermitted);
}
else
{
System.out.print("\nIncorrect input. Number must be a positive integer.\n");
counter++;
}
if(counter>=3)
{
System.out.println("3 strikes and you're out!");
System.exit(0);
}
} while (playAgain != false);
}
}
In the future, I recommend you research your questions on the internet before bringing the question here. There were several other places that could've easily answered your question.
Now as for your actual question, notice how I changed your code at the line that says s = input.nextLine()? What I did there is checked to see if each digit in the string was any number between and including 0-9. Not only was I able to check if they were all numbers, but I was also able to see if they were all positive too as you would have to put a - in order for it to be negative. Along with that, you also have a boolean that only works when the input is a positive number. If not, it checks 3 times to make sure your program doesn't mess up. Furthermore, I even commented out another section that allows the 3 strikes to include if answering the yes no question counts as a strike. If there any other questions, just ask and I will edit my answer.

You are trying to take input using Scanner class with
int n = input.nextInt();
If you enter a character in place of number here you will get java.util.InputMismatchException
What you can do is something like
try {
int n = input.nextInt();
} catch (InputMismatchException e) {
//handle the error scenario where the input is a character
System.out.println("Enter Valid Input");
}