I want to give the user a choice to quit the program while the program is running whenever they feel like it. E.g. Press Q and ENTER at anytime to quit and end program.
I have a try and catch method but whenever I press Q and ENTER, it just displays whats in the catch part.
Here is the code:
public static void partB() {
//Code for partB goes here.
//Continues on with partA but with few changes
/* The number of multiplication problems should not be fixed. Instead,
the program should keep posing new multiplication problems until the user decides to quit by entering the letter "q".
The program should be able to deal with invalid input by the user.
It should ignore such input and restate the current multiplication problem.
*/
//Uses the imported Random function.
Random num = new Random();
//Initialises the minimum and maximum numbers.
int minNumber = 10; //Minimum number to start random
int maxNumber = 20; //Maximum number to start random
int counter = 0; //Counts the number of questions answered.
int correctAnswers = 0; //Counts the number of correct answers given.
final int numberOfQuestions = 0;
while(numberOfQuestions >= 0) {
//Generates a random integer between 10 and 20.
int randInt1 = (num.nextInt(maxNumber - minNumber) + minNumber);
//Repeats for the 2nd integer to get the product of the two numbers.
int randInt2 = (num.nextInt(maxNumber - minNumber) + minNumber);
//Initialise the Scanner function.
Scanner input = new Scanner(System.in);
//Output the Question.
System.out.println("What is " + randInt1 + " X " + randInt2 + "?" + " " + "(Press 'q' and ENTER to quit)");
//Waits for user input.
try {
int userInput = input.nextInt();
String quit = input.nextLine();
//If user input is 'q', quit program.
if(quit.equalsIgnoreCase("q")) {
System.out.println("Exiting...");
System.exit(0);
} else {
int answer = randInt1 * randInt2;
//Checks if the users input is correct.
if (answer == userInput) {
System.out.println("That is correct!");
correctAnswers++;
}
else {
System.out.println("That is incorrect! " + "The correct answer should be " + answer);
counter++;
}
}
} catch(InputMismatchException e) {
System.out.println("You have entered something other than an integer or 'q'! Please try again with a different question!");
}
}
}
If you want to accept both a number and a letter, it is better to use nextLine(). First you check for q, and then parse to number, as follows (note that parseInt will throw a NumberFormatException):
try {
String userInput = input.nextLine();
// If user input is 'q', quit program.
if (userInput.equalsIgnoreCase("q")) {
System.out.println("Exiting...");
System.exit(0);
} else {
int userAnswer = Integer.parseInt(userInput);
int answer = randInt1 * randInt2;
// Checks if the users input is correct.
if (answer == userAnswer) {
System.out.println("That is correct!");
correctAnswers++;
} else {
System.out.println("That is incorrect! " + "The correct answer should be " + answer);
counter++;
}
}
} catch (NumberFormatException e) {
System.out.println(
"You have entered something other than an integer or 'q'! Please try again with a different question!");
}
Related
I have been working on a java guessing game for letters (a-z)! However i have created the game perfectly by using the number 1-26, but i cannot figure out how to convert each integer to a letter ie a = 1, b = 2,....z = 26!
I want the user to try and guess the letter and not the number, but i cannot workout how to do this!
(I know how to generate a random character but i cant implement and link it to each integer within the game correctly)
Random r = new Random();
char targetLetter = (char)(r.nextInt(26) + 'a');
Any help would be greatly appreciated! And i can display my code if it is needed
public class Stack {
public static void main(String[] args) {
Random rand = new Random(); //This is were the computer selects the Target
int guess;
int numGuesses = 0;
int Target;
String userName;
String playagain;
boolean play = true;
int session = 0;
int sessions = 0;
int bestScore = 0;
Scanner consoleIn = new Scanner(System.in);
Scanner name = new Scanner(System.in);
System.out.println("Hello! Please enter your name:\n"); //This is were the user enters his/her name
userName = name.nextLine();
System.out.println("Hello " + userName + " :) Welcome to the game!\n");
while (play = true) {
session++;
Target = rand.nextInt(26) + 1;
System.out.println("Guess a number between 1 and 26? You will have 5 attempts to guess the correct number"); //This is where the computer asks the user to guess the number and how many guesses they will have
do {
guess = consoleIn.nextInt();
numGuesses++;
if (guess > 26)
System.out.println("Error! Above MAXIMUM range");
else if (guess <= 0)
System.out.println("Error! Below MINIMUM range");
else if (guess > Target)
System.out.println("Sorry! Your guess was too high! :)"); //This is to help the player get to the answer
else if (guess < Target)
System.out.println("Sorry! Your guess was too low! :)"); //This is to help the player get to the answer
} while (guess != Target && numGuesses < 5);
if (guess == Target) {
System.out.println("Congratulations " + userName + ", it took you " + numGuesses + " attempts to guess correctly!"); //This tells the player that they got the correct answer and how many attempts it took
sessions++;
} else {
System.out.println("Sorry " + userName + ", You've used up all of your guesses! The correct answer was " + Target + "!"); //This tells the player that they failed to find the number and then tells them what the correct answer
}
{
Scanner answer = new Scanner(System.in);
System.out.println("Would you like another GO " + userName + "? [Y/N]");//This asks the player if they would like to play again
playagain = answer.nextLine();
if (playagain.equalsIgnoreCase("Y")) {//This is what happens if the player opts to play again
play = true;
numGuesses = 0;
} else if (playagain.equalsIgnoreCase("N")) {//This is what happens if the player opts to exit the game
play = false;
System.out.println("Thanks for playing " + userName + "! :) Please come back soon!");
System.out.println("You had " + session + " Goes");
System.out.println("The number of times you guessed correctly: " + sessions + "");
break;
}
}
}
}
}
use arrays of characters
char[] chars = ['A','B','C'...];
and use the random numbers to map to each character
char targetLetter = chars[r.nextInt(26)];
public static void main(String args[])
{
Scanner scan = new Scanner(System.in);
System.out.println("Guess the Letter");
String myLetter=scan.nextLine();
//get the letter of myLetter variable then convert to Uppercase
char enteredLetter=Character.toUpperCase(myLetter.charAt(0));
//26 only because the characters array starts with index 0
char[] characters ={'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
//I had created a parrallel array symbolizing int value of each letter
int[] range={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26};
//this variable convert user input to one of the array element of range
int userInputToInt=0;
//this variable is for knowing what int[] range array element must the value of userInputToInt fall
int userInputControlLoop=0;
char randomLetter=characters[(int)(Math.random()*26)];
// get the random input of computer convert it to int
int computerInputToInt=0;
//this loop is for getting the int value of randomLetter input by the computer
for(int i=0;i<characters.length;++i)
{
if(randomLetter==characters[i])
{
computerInputToInt=range[i];
}
}
//this loop is for getting the int value of user inputted letter
for(char i:characters)
{
if(enteredLetter==i)
{
userInputToInt=range[userInputControlLoop];
}
++userInputControlLoop;
}
//test the entered letter of user
if(enteredLetter==randomLetter)
{
System.out.println("Correct Guess");
System.out.println("The letter is:"+randomLetter);
}
//test the entered letter of user if greater than computer input
else if(userInputToInt>computerInputToInt)
{
System.out.println("Incorrect Guess");
System.out.println("The letter is too high");
System.out.println("The letter is:"+randomLetter);
}
//test the entered letter of user if lesser than computer input
else if(userInputToInt<computerInputToInt)
{
System.out.println("Incorrect Guess");
System.out.println("The letter is too low");
System.out.println("The letter is:"+randomLetter);
}
}
Use the same method that you do for your random characters. Assuming you have your guessed character as an int variable called "guess", and it has value 1-26 corresponding A-Z:
Random r = new Random();
char targetLetter = (char)(r.nextInt(26) + 'a');
...
int guess = ...
char guessChar = (char)guess + 'a';
if (guessChar == targetLetter) {
System.out.println("Correct!");
} else {
System.out.println("Guess again!")
}
You can implement it in this approach :
1- Create a String alphabet with the characters that you want.
2- declare the size of alphabet as n variable which will control the random generator range.
3- alphabet.charAt(random.nextInt(n)) is a random char from the alphabet.
program code will be :
String alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
int n = alphabet.length();
Random r = new Random();
System.out.println(alphabet.charAt(r.nextInt(n)));
hope will help solve your problem.
public class Picnic1 {
// RULE 0: This code is provided as a working example.
// This rule tests for whether a word starts with the letter 'b' (allowed to the picnic).
public static boolean rule0(char[] array) {
if (array[0] == 'b') {
return true;
}
else {
return false;
}
// itemMessage:
// Return message about whether a particular item is allowed to the picnic.
public static String item ( double[] a){
// This code works, providing output like these examples:
// "banana: true"
// "collie: false"
// It needs to be replaced with a more suitable output.
// Instead it should return, for example:
// "Yes, you can bring a banana to the picnic."
// "No, you cannot bring a collie to the picnic."
if (a[0] == 'b') {
System.out.println("Yes, you can bring a" + 'a' + "to the picnic");
}
else if (a[0] != 'b') {
System.out.print("No, you can not bring a " + 'a' + "to the picnic");
}
}
}
}
I have a program that asks the user their name etc. Then it asks how many times do you want the numbers to loop (so my program generates 3 random numbers between 7 and 13 and if it adds up to 31 they are the winner) and my issue is that I only want the last printed number to count towards if the player wins or looses, the other numbers are just for show or tease i guess. the problem is that regardless towards if the player wins or looses, the losing statement always prints out. Below is my entire code.
import java.util.InputMismatchException;
import java.util.Scanner;
import java.io.IOException;
import java.util.Random;
public class StringVariables {
public static void main(String[] args) throws NumberFormatException,
IOException {
// user inputs their name in this section
Scanner user_input = new Scanner(System.in);
//enter their first name
String first_name;
System.out.print("Enter Your First Name: ");
while
(!user_input.hasNext("[A-Za-z]+")) {
System.out.println("Please only enter alphabet characters. Try again.");
user_input.next();
}
first_name = user_input.next();
//enter their last name
String last_name;
System.out.print("Enter Your Last Name: ");
while
(!user_input.hasNext("[A-Za-z]+")) {
System.out.println("Please only enter alphabet characters. Try again.");
user_input.next();
}
last_name = user_input.next();
//full name printed together
String full_name;
full_name = first_name + " " + last_name;
System.out.println(full_name + " Is Now Playing");
// this is the shuffle portion as well as something to see if a number
int numShuffles = -1;
while (numShuffles < 0) {
System.out.println("How many times do you want the numbers shuffled? ");
try {
numShuffles = user_input.nextInt();
} catch (InputMismatchException inputException) {
System.out.print("Please enter a valid number. \n");
//this is the buffer that resets if the user types a letter instead of a number, or any other character
user_input.next();
}
}
// here is going to be the loop for shuffles
// we are now going to generate their random number and add a delay
// after completing their name fields
delay(3000);
System.out
.println(" You will be given " + numShuffles + " hand(s) of 3 random numbers between 7-13" );
delay(2000);
System.out
.println(" Then, the computer will add the random numbers and if it is equal to 31, you win!");
/*
* end of explanation of the game, next i will create a new screen with
* the user's name and numbers
*/
delay(4000);
// printing 25 blank lines
for (int i = 0; i < 25; i++)
System.out.println(" ");
System.out.println("User playing: " + full_name);
System.out.println("Number of times shuffled: " + numShuffles);
System.out.println("Your lucky numbers are...");
// random number generator
Random random = new Random();
while (true) {
// the shuffle loop
Arraylist numberStore = new Arraylist();
boolean isWinner = false;
for (int i = 0; i < numShuffles; i++) {
int num1 = 7 + random.nextInt(7);
int num2 = 7 + random.nextInt(7);
int num3 = 7 + random.nextInt(7);
System.out.println(num1 + " + " + num2 + " + " + num3 + " = " + (num1 + num2 + num3));
numberStore.add(num1 + num2 + num3);
int lastNumber = (numberStore.size() - 1);
if (lastNumber == 31) {
isWinner = true;
System.out.println("Congratulations !! You are the Lucky Winner !!!!");
break;
//if you loose every shuffle
}
}
if (!isWinner) {
System.out.println("Better Luck Next Time");
}
// play again prompt
System.out
.println(" Do you want to play again? (If you do enter y or yes) \n To exit press any other key ");
String input = user_input.next();
if (!"y".equalsIgnoreCase(input) && !"yes".equalsIgnoreCase(input)) {
break;
}
}
// if pressed y or yes the program will run again with the same number of shuffles entered from before
user_input.close();
}
// delay field
public static void delay(int millis) {
try {
Thread.sleep(millis);
} catch (InterruptedException exp) {
// delay field
}
}
}
int lastNumber = (numberStore.size() - 1);
if (lastNumber == 31) {
you probably want something like
int lastNumber = numberStore.get(numberStore.size() - 1);
if (lastNumber == 31) {
to verify that is the error try to change that line to
int lastNumber = num1 + num2 + num3;
Edit based on further messages:
Looks like what you really want is this:
for (int i = 0; i < numShuffles; i++) {
int num1 = 7 + random.nextInt(7);
int num2 = 7 + random.nextInt(7);
int num3 = 7 + random.nextInt(7);
System.out.println(num1 + " + " + num2 + " + " + num3 + " = " + (num1 + num2 + num3));
numberStore.add(num1 + num2 + num3);
int lastNumber = num1 + num2 + num3;
boolean lastShuffle = (i == (numShuffles - 1));
if (lastShuffle) {
if (lastNumber == 31) {
System.out.println("Congratulations !! You are the Lucky Winner !!!!");
} else {
System.out.println("Better Luck Next Time");
}
}
}
// play again prompt
System.out
.println(" Do you want to play again? (If you do enter y or yes) \n To exit press any other key ");
String input = user_input.next();
if (!"y".equalsIgnoreCase(input) && !"yes".equalsIgnoreCase(input)) {
break;
}
Just a general suggestion: avoid to use break if possible, it makes control flow hard to follow and is not a good programming practice.
Several points to make here. One, your code is quite messy and hard to read. It's helpful when you're asking for help (and in general anyway) to properly indent your code. This is good practice and if you do other languages like Python can help you out a lot. Also, why do a check for !isWinner? Scrap the isWinner variable altogether and just check for the number equalling 31 and then have an else statement for the losing statement. Like this:
if (lastNumber == 31) {
System.out.println("Congratulations !! You are the Lucky Winner !!!!");
break;
//if you loose every shuffle
}
else {
System.out.println("Better Luck Next Time");
}
Also, take some steps to find the error. Print out each number as you get it, and use
int lastNumber = num1 + num2 + num3;
instead of
int lastNumber = (numberStore.size() - 1);
Also for anybody else compiling this, it's ArrayList and not Arraylist... just a little slip.
Sorry, I may have to say that your codes are a kind of mess up. a small factory with the solution you ask, hope it can be a little help to you
public static void main(String[] args) throws NumberFormatException,
IOException {
Scanner user_input = new Scanner(System.in);
String full_name = registeGamePlayer(user_input);
int numShuffles = initGame(user_input);
showTheGameInfo(full_name, numShuffles);
runningGame(user_input, numShuffles);
user_input.close();
}
/**
* #param user_input
* #param numShuffles
*/
private static void runningGame(Scanner user_input, int numShuffles) {
// random number generator
Random random = new Random();
while (true) {
// the shuffle loop
boolean isWinner = false;
for (int i = 0; i < numShuffles; i++) {
int num1 = 7 + random.nextInt(7);
int num2 = 7 + random.nextInt(7);
int num3 = 7 + random.nextInt(7);
int amount = num1 + num2 + num3;
System.out.printf("%d + %d + %d = %d \n", num1,num2,num3,amount);
if (amount == 31) {
isWinner = true;
System.out.println("Congratulations !! You are the Lucky Winner !!!!");
break;
// if you loose every shuffle
}
}
if (!isWinner) {
System.out.println("Better Luck Next Time");
}
// play again prompt
System.out.println(" Do you want to play again? (If you do enter y or yes) \n To exit press any other key ");
String input = user_input.next();
if (!"y".equalsIgnoreCase(input) && !"yes".equalsIgnoreCase(input)) {
break;
}
}
}
/**
* #param full_name
* #param numShuffles
*/
private static void showTheGameInfo(String full_name, int numShuffles) {
// printing 25 blank lines
for (int i = 0; i < 25; i++)
System.out.println(" ");
System.out.println("User playing: " + full_name);
System.out.println("Number of times shuffled: " + numShuffles);
System.out.println("Your lucky numbers are...");
}
// delay field
public static void delay(int millis) {
try {
Thread.sleep(millis);
} catch (InterruptedException exp) {
// delay field
}
}
private static String registeGamePlayer(Scanner user_input){
String first_name;
System.out.print("Enter Your First Name: ");
while (!user_input.hasNext("[A-Za-z]+")) {
System.out
.println("Please only enter alphabet characters. Try again.");
user_input.next();
}
first_name = user_input.next();
// enter their last name
String last_name;
System.out.print("Enter Your Last Name: ");
while (!user_input.hasNext("[A-Za-z]+")) {
System.out
.println("Please only enter alphabet characters. Try again.");
user_input.next();
}
last_name = user_input.next();
// full name printed together
String full_name;
full_name = first_name + " " + last_name;
System.out.println(full_name + " Is Now Playing");
return full_name;
}
private static int initGame(Scanner user_input){
// this is the shuffle portion as well as something to see if a number
int numShuffles = -1;
while (numShuffles < 0) {
System.out.println("How many times do you want the numbers shuffled? ");
try {
numShuffles = user_input.nextInt();
} catch (InputMismatchException inputException) {
System.out.print("Please enter a valid number. \n");
// this is the buffer that resets if the user types a letter
// instead of a number, or any other character
user_input.next();
}
}
// here is going to be the loop for shuffles
// we are now going to generate their random number and add a delay
// after completing their name fields
delay(3000);
System.out.println(" You will be given " + numShuffles + " hand(s) of 3 random numbers between 7-13");
delay(2000);
System.out.println(" Then, the computer will add the random numbers and if it is equal to 31, you win!");
/*
* end of explanation of the game, next i will create a new screen with
* the user's name and numbers
*/
delay(4000);
return numShuffles;
}
So I'm working on a copy of a simple Dice game that was an example from the Maxwell Sanchez YouTube JAVA on Eclipse tutorials. What I started playing around with is simple ways to implement a text based menu of sorts.
What I'm trying to accomplish is a Y or N input method of either restarting the program, or killing it. I'm a total noob, coming here after a tiny bit of Arduino. I'm liking JAVA but there are many things I don't understand.
My problem right now is, everything appears to work so far, except that if you get to the end and type N to quit, It requires 2 inputs of N to actually execute the else if statement. Is that something that is a bug? Or am I just mis-programing what I'm trying to accomplish.
import java.util.*;
public class diceGame
{
static int money;
static Scanner in = new Scanner(System.in);
static Random random = new Random();
static String userName;
static String tryAgain;
public static void main(String[] args)
{
money = 1000;
System.out.println("Welcome to this simple dice game! " +
"Please enter your name.");
String userName = in.nextLine();
System.out.println("Hey " + userName + ".");
rollDice();
}
public static void rollDice()
{
System.out.println("You have " + money + " coins!");
System.out.println("Please select a number (1-6) to bet on!");
int betRoll = in.nextInt();
System.out.println("Please place your bet!");
int betMoney = in.nextInt();
while (betMoney > money)
{
System.out.println("You don't have enough coins... you only " +
"have " + money + "coins.");
System.out.println("Please place a realistic bet!");
betMoney = in.nextInt();
}
int dice;
dice = random.nextInt(6)+1;
if (betRoll == dice)
{
System.out.println("You Win!");
money+=betMoney*6;
System.out.println("You have " + money + " coins.");
}
else
{
System.out.println("Snap! You lost your coins!");
money-=betMoney;
System.out.println("You have " + money + " coins.");
}
if (money <= 0)
{
System.out.println("You've lost all yer coins!");
System.out.println("Play again?" + " Type y or n");
if (in.next().equalsIgnoreCase("y"))
{
System.out.println("Maybe you'll win this time!");
money = 1000;
rollDice();
}
else if (in.next().equalsIgnoreCase("n"))
{
System.out.println("Maybe next time...");
System.exit(0);
}
else
{
System.out.println("Invalid character");
}
}
else
{
rollDice();
}
}
}
Store the input in a variable, and compare it... or you'll have to input twice.
String choice = in.next();
if (choice.equalsIgnoreCase("y"))
{
System.out.println("Maybe you'll win this time!");
money = 1000;
rollDice();
}
else if (choice.equalsIgnoreCase("n")) // <-- not in.next()
Every time you call in.next() you read user input.
if (in.next().equalsIgnoreCase("y"))
else if (in.next().equalsIgnoreCase("n"))
In this code, you are calling in.next() twice, once for each condition, so it will read two inputs.
You need to separate the reading from the comparison.
String input = in.next();
if (input.equalsIgnoreCase("y"))
else if (input.equalsIgnoreCase("n"))
This program's objective is to calculate the n-th Fibonacci number. How do I allow the user to continue entering numbers until they choose to quit? Thanks.
public class FibonacciNUmbers
{
public static int calcFibNum(int x)
{
if (x == 0)
return 0;
else if (x == 1)
return 1;
else
return calcFibNum(x-1) + calcFibNum(x-2);
}
public static void main(String[] args)
{
Scanner in = new Scanner(System.in);
System.out.println("What number would you like to find the Fibonacci number for?");
int x = in.nextInt();
System.out.println("The Fibonacci number of " + x + " is " + calcFibNum(x));
System.out.println("Would you like to find the Fibonaci number of another number?");
String answer = in.next();
if (answer.equalsIgnoreCase("Y"));
{
System.out.println("What number would you like to find the Fibonacci number for?");
x = in.nextInt();
System.out.println("The Fibonacci number for " + x + " is " + calcFibNum(x));
}
else
{
System.out.println();
}
}
}
By the way your code prints all the Fibonacci numbers up to n and not the nth number.Below is just an example of how to keep entering input from Scanner. Use that to build upon what you want to do:
int num = 0;
while (in.hasNextInt()) {
num = in.nextInt();
}
Happy coding!
//start your while loop here
while (true)
{
System.out.println("Would you like to find the Fibonacci number of another number?");
String answer = in.next();
if (answer.equalsIgnoreCase("Y"));
{
System.out.println("What number would you like to find the Fibonacci number for?");
x = in.nextInt();
System.out.println("The Fibonacci number for " + x + " is " + calcFibNum(x));
}
else
{
System.out.println("Thanks for playing");
break; // ends the while loop.
}
}
For loops are used when you can count things or have a set of things. While loops are used when you're not sure how long it might go on for, or if you want it to continue until some event occurs (user pressing a certain letter for example)
Slight variation of the above that is probly a bit more elegant:
String answer = "Y";
//start your while loop here
while (answer.equals("Y")) {
System.out.println("Would you like to find the Fibonacci number of another number?");
answer = in.next(); //declare your variable answer outside the loop so you can use it in the evaluation of how many times to do the loop.
if (answer.equalsIgnoreCase("Y"));
{
System.out.println("What number would you like to find the Fibonacci number for?");
x = in.nextInt();
System.out.println("The Fibonacci number for " + x + " is " + calcFibNum(x));
}
else
{
System.out.println("Thanks for playing");
// no need to break out.
}
}
In this Java program the user is supposed to guess a number from 1 to 100, and then if you press S it shows you a summary of the tries. The problem is that I am taking the input string and converting it to a number so I can compare it to the range, but then I also need to be able to use that string as a menu input.
UPDATE How can i make the program go back to the menu option after the user guesses correctly. So after the user wins, i would like for the problem to display the summary report which can be otherwise accessed by using S
Here is my code
public class GuessingGame {
public static void main(String[] args) {
// Display list of commands
System.out.println("*************************");
System.out.println("The Guessing Game-inator");
System.out.println("*************************");
System.out.println("Your opponent has guessed a number!");
System.out.println("Enter a NUMBER at the prompt to guess.");
System.out.println("Enter [S] at the prompt to display the summary report.");
System.out.println("Enter [Q] at the prompt to Quit.");
System.out.print("> ");
// Read and execute commands
while (true) {
// Prompt user to enter a command
SimpleIO.prompt("Enter command (NUMBER, S, or Q): ");
String command = SimpleIO.readLine().trim();
// Determine whether command is "E", "S", "Q", or
// illegal; execute command if legal.
int tries = 0;
int round = 0;
int randomInt = 0;
int number = Integer.parseInt(command);
if (number >= 0 && number <= 100) {
if(randomInt == number){
System.out.println("Congratulations! You have guessed correctly." +
" Summary below");
round++;
}
else if(randomInt < number)
{
System.out.println("your guess is TOO HIGH. Guess again or enter Q to Quit");
tries++;
}
else if(randomInt > number){
System.out.println("your guess is TOO LOW. Guess again or enter Q to Quit");
tries++;
}
} else if (command.equalsIgnoreCase("s")) {
// System.out.println("Round Guesses");
// System.out.println("-------------------------");
// System.out.println(round + "" + tries);
} else if (command.equalsIgnoreCase("q")) {
// Command is "q". Terminate program.
return;
} else {
// Command is illegal. Display error message.
System.out.println("Command was not recognized; " +
"please enter only E, S, or q.");
}
System.out.println();
}
}
}
You should check for the S/Q value first, then parse the string to an integer. If you catch NumberFormatException (thrown by Integer.parseInt()), you can determine if the input is a valid value. I would do something like that:
if ("s".equalsIgnoreCase(command)) {
// Print summary
} else if ("q".equalsIgnoreCase(command)) {
// Command is "q". Terminate program.
return;
} else {
try {
Integer number = Integer.parseInt(command);
if(number < 0 || number > 100){
System.out.println("Please provide a value between 0 and 100");
} else if(randomInt == number){
System.out.println("Congratulations! You have guessed correctly." +
" Summary below");
round++;
} else if(randomInt < number) {
System.out.println("your guess is TOO HIGH. Guess again or enter Q to Quit");
tries++;
} else if(randomInt > number) {
System.out.println("your guess is TOO LOW. Guess again or enter Q to Quit");
tries++;
}
} catch (NumberFormatException nfe) {
// Command is illegal. Display error message.
System.out.println("Command was not recognized; " +
"please enter only a number, S, or q.");
}
}
With this algorithm (I'm sure it can be optimized), you treat following cases:
User enters s/S
User enters q/Q
User enters a non valid value (not a number)
User enters a non valid number (less than 0 or greater than 100)
User enters a valid number
To check if a string is an integer, just attempt to parse it as an integer and if an exception is thrown, then it is not an Integer.
See:
http://bytes.com/topic/java/answers/541928-check-if-input-integer
String input = ....
try {
int x = Integer.parseInt(input);
System.out.println(x);
}
catch(NumberFormatException nFE) {
System.out.println("Not an Integer");
}
Integer.parseInt(command) will give you NumberFormatException if the String is not valid. It is possible in your code if the user enters 'S' or 'E' which cannot be parsed to int value.
I have modified your code. Check this code :
while (true) {
// Prompt user to enter a command
SimpleIO.prompt("Enter command (NUMBER, S, or Q): ");
String command = SimpleIO.readLine().trim();
// Determine whether command is "E", "S", "Q", or
// illegal; execute command if legal.
int tries = 0;
int round = 0;
int randomInt = 0;
if(!command.equals("S") && !command.equals("E")) {
// Only then parse the command to string
int number = Integer.parseInt(command);
if (number >= 0 && number <= 100) {
if(randomInt == number){
You're trying to convert the incoming String to an int before you check if its an escape sequence (S or Q).
Try rearranging your if statement to check for S and Q first then try converting the value to an int.
I'd also recommend you wrap the Integer.parseInt call (it's subsequent, reliant code) in a try-catch block, so you can provided an error statement to the user if they type in anything that isn't an int