I'm not entirely sure what I'm doing wrong at this point. I've been getting the same two errors:
CoffeeBot.java:79: illegal start of expression
}
CoffeeBot.java:82: reached end of file while parsing
} //public class
2 errors
Someone correct me thanks?
import java.util.Scanner ;
public class CoffeeBot {
public static void main(String[] args) {
int n1 = Integer.parseInt(args[0]);
int n2 = Integer.parseInt(args[1]);
for (int i = 0;i<args.length;i++) // REMEMBER TO PUT IN ARGS LENGTH
if (!(n1 > 0) && !(n2 > 0)) { // This is for both negative inputs n1 and n2
System.out.println("Negative supply chain. System terminating.");
return;
}
if (n1 < 0) { // This is for negative input n1
System.out.println("Negative supply of coffee cups. System terminating.");
return;
}
if (n2 < 0) { // This is for negative input n2
System.out.println("Negative supply of coffee shots. System terminating.");
return;
}
else {// If inputs comply with rules then proceed to here
System.out.println("Hello, what's your name?");
String name;
Scanner keyboard = new Scanner(System.in);
name = keyboard.next();
System.out.println("Would you like to order some coffee, " + name + "? (y/n)");
String yesno;
yesno = keyboard.next();
if (yesno.equalsIgnoreCase("y")) {
System.out.println("Great! Let's get started.");
System.out.println(" ");
System.out.println("Order selection");
System.out.println("---------------");
System.out.println(" ");
}
if (yesno.equalsIgnoreCase("n")) {
System.out.println("Come back next time, " + name +".");
return;
}
else {
System.out.println("Invalid response. Try again.");
while (yesno.toIgnoreCase("n"))
while (yesno.toIgnoreCase("y"))
}
}//else
} //main args
} //public class
yesno is of type String.
while (yesno.toIgnoreCase("n"))
while (yesno.toIgnoreCase("y"))
there is no toIgnoreCase() method , i guess you meant equalsIgnoreCase().also put ; after the 2nd while loop better yet use {} all the time.
Related
I'm making a very simple program that asks a user to input an age and then it will calculate a charge for admission. So far all works well but I'm wanting to add a check in so that if the user inputs anything other than an int value, it will ask them to enter an int value. I.e if they enter a character.
Here is my code:
public class CalcChargeAge {
public static void main(String[] args) {
int x;
double chargeA = 20;
double chargeB = 10;
System.out.println("Enter Users age to calculate charge for entry. ");
Scanner in = new Scanner(System.in);
x = in.nextInt();
if (x >= 18) {
System.out.println("Users age is " + x);
System.out.println("Please pay the charge for entry: £" + chargeA);
} else if (x >= 12) {
System.out.println("Users age is " + x);
System.out.println("Please pay the charge for entry: £" + chargeB);
} else {
System.out.println("Users age is " + x);
System.out.println("User entry charge is free. Print admission ticket.");
}
}
}
You can use the Scanner.hasNextInt() method to check whether the input is an integer, which I think is a lot nicer than catching an exception.
Then for the full implementation you could wrap everything in a loop, so you could do something like:
Scanner in = new Scanner(System.in);
while(in.hasNext()) {
if(in.hasNextInt()) {
int x = in.nextInt();
// Handle input
break;
}
else {
// Handle invalid input
in.next();
}
}
Something like this should work fine:
boolean isValid = false;
int validInput = 0;
while (!isValid) {
try {
validInput = scanner.nextInt();
isValid = true;
}
catch (Exception e) {
System.out.println("Please enter a valid integer.");
}
}
// ... code using validInput
One of the ways (beware, it might not be the best or even the good one) to go about it would be to replace x=in.nextInt(); with
while(true) {
String input = in.next();
try {
x = Integer.parseInt(input);
break;
} catch (Exception e) {
System.out.println("Please provide an integer!");
}
}
this will not leave the loop until user provides an integer value (evil!)
so i made a game, in which user needs to guess the random number or letter. I want to make it so that when the user writes 'end game' during the game (when he guesses the number), he is being redirected to the menu (using the main(args); method). In fact, String value cannot be writen in int input. So when i write 'end game' during the game cycle, it just crashes. What should i do?
Heres code of my game:
import java.util.Scanner;
public class TwoGames {
public static void main(String[] args) { // main menu
Scanner scan = new Scanner(System.in);
System.out.println("Choose the game\n Type 'letter' or 'number' to choose the game");
String UserAnswer = "";
UserAnswer = scan.next();
if (UserAnswer.equalsIgnoreCase("number")) {
number(args);
}else if(UserAnswer.equalsIgnoreCase("letter")){
letter(args);
}
scan.close();
}
public static void letter (String[] args) {
Scanner scan = new Scanner(System.in);
String playAgain = "";
String ReTurn = "";
String Stop = "";
int numberOfTries = 0;
do {
System.out.println("Guess the Letter");
char randomLetter = (char) (Math.random() * 26 + 65);
char enteredLetter = 0;
while(true){
enteredLetter = Character.toUpperCase(scan.next().charAt(0));
numberOfTries = numberOfTries + 1;
if(enteredLetter==randomLetter)
{
System.out.println("Correct Guess");
System.out.println("The letter is:"+randomLetter);
System.out.println("It only took you " + numberOfTries + " tries! Good work!");
break;
}
else if(enteredLetter>randomLetter)
{
System.out.println("Incorrect Guess");
System.out.println("The letter entered is too high");
}
else if(enteredLetter<randomLetter)
{
System.out.println("Incorrect Guess");
System.out.println("The letter entered is too low");
}
}
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! \n Type 'return' to return to main menu");
ReTurn = scan.next();
if (ReTurn.equalsIgnoreCase("return"))
main(args);
scan.close();
}
public static void number(String[] args) { //heres the number guessing game
Scanner scan = new Scanner(System.in);
String playAgain = "";
String ReTurn = "";
String Stop = "";//variable to stop game
do {
int theNumber = (int)(Math.random() * 100 + 1);
int numberOfTries = 0;
do {
int guess = 0;
while (guess != theNumber) {
System.out.println("Guess a number between 1 and 100:");
guess = scan.nextInt();
numberOfTries = numberOfTries + 1;
if (guess < theNumber)
System.out.println(guess + " is too low. Try again.");
else if (guess > theNumber)
System.out.println(guess + " is too high. Try again.");
else {
System.out.println(guess + " is correct. You win!");
System.out.println("It only took you " + numberOfTries + " tries! Good work!");
}
}
} while (Stop.equalsIgnoreCase("end game"));
main(args);// this sends user to main menu
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! \n Type 'return' to return to main menu");
ReTurn = scan.next();
if (ReTurn.equalsIgnoreCase("return"))
main(args);
scan.close();
}
}
I am novice programmer, so yeah, thats might be a dumb question, because im learning. Anyway, any help and explanation would be useful.
To solve this problem, you should input a string, check if it equals to "End game" message and if not continue your code.
For example, replace this line:
guess = scan.nextInt();
In this code:
String input = scan.next();
if(input.equals("End game")){
main(args);
return;
}
guess = Integer.parseInt(input);
That code get a String input called input, check if he equals to "End game" and if not continue your guess loop.
I am working on a project that involves creating a rental car calculator.
What I am trying to do is make it to where when asked: "What vehicle would you like to rent??". If a number that is not between 1-3 is entered when the user is prompted this, then I want the program to loop back to the point of being asked vehicle type again.
Similarly, when prompted for 'Please enter the number of days rented. (Example; 3) : ' I want to only allow the user to input whole positive numbers. for instance, not allowing input of 3.1, 2.35, 0.35 -2 and, etc...
here is what I have written and my attempt at these questions :
package inter;
import java.util.Scanner;
public class Inter {
public static void main(String []args){
int count=0;
int days;
double DailyFee=0, NontaxTotal, CarType, Total,FullTotal=0;
Scanner in=new Scanner(System.in);
System.out.println("If there are any customer press 1 else press 0");
int cus=in.nextInt();
while(cus!=0){
count++;
System.out.print("What vehical would you like to rent?\n");
System.out.println("Enter 1 for an economy car\n");
System.out.println("Enter 2 for a sedan car\n");
System.out.println("Enter 3 for an SUV");
CarType = in.nextInt();
if (CarType == 1) {
DailyFee=31.76;
}
else if(CarType == 2) {
DailyFee=40.32;
}
else if(CarType == 3) {
DailyFee=47.56;
}
else if(CarType <= 0) {
System.out.println("input is not a positive Integer ");
System.out.println("Please enter a positive integer value: ");
cus = 0; }
else if(CarType > 4) {
System.out.println("input is not a positive Integer ");
System.out.println("Please enter a positive integer value: ");
cus = 0; }
System.out.print("Please enter the number of days rented. (Example; 3) : ");
days = Integer.valueOf(in.nextLine());
double x=days;
NontaxTotal = (DailyFee * x);
Total = (NontaxTotal * 1.06);
FullTotal+=Total;
System.out.printf("The total amount due is $ %.2f \n",Total);
System.out.println("If there are any customer press 1 else press 0");
cus=in.nextInt();
}
System.out.println("Count of customers : "+count);
System.out.printf("Total of the Day : $ %.2f",FullTotal);
}
}
Let me help you with this,
I made this code for you, i tried it and it worked
this will check if both answers were whole numbers (integers) and more than zero and will also check if the answer was numeric in the first place so that if the user answered with letters he will be prompted to try again
This is my suggestion:
basically i used the try-catch block with InputMismatchException to detect if the answer was not an integer (whole number ) or was not numeric at all, every time a mistake is detected i flip a boolean to false and keep looping as long as this boolean is false (i flip the boolean back to true before checking otherwise once the user gives a wrong answer he will always be prompted to answer even if he gave a correct answer after)
int vehicleType;
int numberOfDays;
double dailyFee;
boolean validAnswer1 = false;
boolean validAnswer2 = false;
Scanner scan = new Scanner(System.in);
while (validAnswer1 == false) {
validAnswer1 = true;
System.out.println("Choose Vehicle Type");
try {
vehicleType = scan.nextInt();
if (vehicleType <= 0) {
System.out.println("Number must be more than zero");
validAnswer1 = false;
} else if (vehicleType >= 4) {
System.out.println("Number should be from 1 to 3");
validAnswer1 = false;
} else {
if (vehicleType == 1) {
dailyFee=31.76;
} else if(vehicleType == 2) {
dailyFee=40.32;
}else if(vehicleType == 3) {
dailyFee=47.56;
}
while (validAnswer2 == false) {
validAnswer2 = true;
try {
System.out.println("Enter number of days rented ?");
numberOfDays = scan.nextInt();
if (numberOfDays <= 0) {
System.out.println("Number of days must be more than zero");
validAnswer2 = false;
} else {
// calculate your rent total here
}
} catch(InputMismatchException ex) {
System.out.println("Answer must be an Integer");
validAnswer2 = false;
scan.next();
}
}
}
} catch (InputMismatchException ex) {
validAnswer1 = false;
System.out.println("Answer must be an Integer");
scan.next();
}
}
Hope this was useful, do let me know if you still need help
I am just playing around with java and wanted to make a simple program where the user; me has to guess/type in the correct number until it's correct. What can I do so the program can keep running, printing out "Make another guess" until the user/me puts in the correct number. Maybe a boolean? I'm not sure. This is what I have so far.
import java.util.Scanner;
public class iftothemax {
public static void main(String[] args) {
int myInt = 2;
// Create Scanner object
Scanner input = new Scanner(System.in);
//Output the prompt
System.out.println("Enter a number:");
//Wait for the user to enter a number
int value = input.nextInt();
if(value == myInt) {
System.out.println("You discover me!");
}
else {
//Tell them to keep guessing
System.out.println("Not yet! You entered:" + value + " Make another guess");
input.nextInt();
}
}
You might want to use a while loop to repeat some code:
while (value != myInt) {
System.out.println("Not yet! You entered: " + value + ". Make another guess");
value = input.nextInt();
}
System.out.println("You discovered me!");
This program would do the trick:
public static void main(String [] args){
int myInt = 2;
int value = 0;
Scanner input = new Scanner(System.in);
boolean guessCorrect = false;
while(!guessCorrect){
System.out.println("Not yet! You entered:" + value + " Make another guess");
value = input.nextInt();
if(value == myInt){
guessCorrect = true
}
}
System.out.println("You discover me!");
}
Simply introduce a loop.
import java.util.Scanner;
public class iftothemax {
public static void main(String[] args) {
int myInt = 2;
// Create Scanner object
Scanner input = new Scanner(System.in);
for(;;) {
//Output the prompt
System.out.println("Enter a number:");
//Wait for the user to enter a number
int value = input.nextInt();
if(value == myInt) {
System.out.println("You discover me!");
break;
}
else {
//Tell them to keep guessing
System.out.println("Not yet! You entered:" + value + " Make another guess");
}
}
}
}
First of all, I'd like to say that I am REALLY new to all of this... I've tried learning as much as I can, so apologies if any of my code seems ridiculous or all-over-the-place, but I needed somewhere to start. (By the way, credit to the very base of this code goes to CrossCoastGaming: http://tinyurl.com/kktyq4e).
Now to the matter at hand. I have improved (for lack of a better word) on the coding that the man in the video shows, by adding several different phrases, making use of variables and adding a try counter. Here is my code:
import java.util.Random;
import java.util.Scanner;
public class Main {
public static int number, guess, tryCount, replay;
public static int maxValue =1;
public static Scanner scan;
public static Random rand;
public static void main(String args[]) {
scan = new Scanner(System.in);
rand = new Random();
System.out.print("Enter a maximum number: ");
while(maxValue < 2)
maxValue = scan.nextInt();
number = rand.nextInt(maxValue);
System.out.print("Guess a number from 1 to " + maxValue + ": ");
while (guess != number) {
guess = scan.nextInt();
tryCount++;
if (guess < 1) {
System.out.print("Guess is not positive. Try again: ");
}else if (guess < number) {
System.out.print("Too low! Try again: ");
}
if (guess > maxValue) {
System.out.println("Guess is higher than " + maxValue + ". Try again: ");
}else if (guess > number) {
System.out.print("Too high! Try again: ");
}
}
if (tryCount == 1) {
System.out.println("Nailed it! It only took you 1 try!");
}
else {
System.out.println("Nailed it! It took you " + tryCount + " tries.");
}
System.out.println("Type 0 to play again. Type 1 to quit.");
if (replay == 1) {
replay = scan.nextInt();
}
}
}
Ok, so hopefully that gives anyone who knows what they're doing an idea of my goal. Now, as you can see by this line:
if (replay == 1) {
replay = scan.nextInt();
}
I would like to write a way so people can replay the game without having to reboot the file. I already have an idea of what I kind of would like to do, but I've searched everywhere and can't seem to find out what to continue with after this point. I'm sure that I'm missing something. Any help would be greatly appreciated.
You can use a do-while loop to achieve this:
import java.util.Random;
import java.util.Scanner;
public class Main {
public static int number, guess, tryCount, replay;
public static int maxValue = 1;
public static Scanner scan;
public static Random rand;
public static void main(String args[]) {
scan = new Scanner(System.in);
rand = new Random();
do { // start of do-while loop
tryCount = 0; // reset tryCount
System.out.print("Enter a maximum number: ");
while(maxValue < 2) {
maxValue = scan.nextInt();
}
number = rand.nextInt(maxValue);
System.out.print("Guess a number from 1 to " + maxValue + ": ");
while (guess != number) {
guess = scan.nextInt();
tryCount++;
if (guess < 1) {
System.out.print("Guess is not positive. Try again: ");
} else if (guess < number) {
System.out.print("Too low! Try again: ");
}
if (guess > maxValue) {
System.out.println("Guess is higher than " + maxValue + ". Try again: ");
} else if (guess > number) {
System.out.print("Too high! Try again: ");
}
}
if (tryCount == 1) {
System.out.println("Nailed it! It only took you 1 try!");
} else {
System.out.println("Nailed it! It took you " + tryCount + " tries.");
}
do { // check the user's input
System.out.println("Type 0 to play again. Type 1 to quit.");
replay = scan.nextInt();
if (replay != 0 && replay != 1) {
System.out.println("Input not recognized.");
}
} while (replay != 0 && replay != 1);
} while (replay == 0); // end of do-while loop
}
}
do-while loops are always executed at least once. The condition is checked at the end of the loop.