Develop Reference

How do i make a card game with Print statements that only allows each card to be used a specific number of times?

I'm working on a card game for a personal project and I was wondering how I could make it so that each specific card can only be used a set number of times. I'm thinking about making an loop that adds to a specific number, and if the number reaches that specific value, the card can no longer be played. My issue is that I am having trouble with syntax and have just been confusing myself. cardLimiter is the variable i want to use to add to a specific value, though I just need a few pointers. Thanks!
public static void emperorsTurn() {
Random cards = new Random();
int computerinput = 0;
int numberx = 5;
for (int counter = 1; counter <= 3; counter++) {
computerinput = 1 + cards.nextInt(2);
}
Scanner sc = new Scanner(System.in);
System.out.println("Please pick the card you are playing. \n if you are playing the Emperor press 1, if you are playing the citizen press 2 ");
int userinput = sc.nextInt();
if (userinput == 1 && computerinput == 1 && cardLimiter == 0) {
System.out.println("you have played the emperor! \n the emperor is defeated by the slave");
cardLimiter++;
if ((userinput == 1 && computerinput == 1 && cardLimiter == 1)) {
System.out.println("you cannot play the emperor this turn \n you have played the citizen instead");
}
} else if (userinput == 1 && computerinput == 2) {
System.out.println("you have played the emperor the emperor defeats the citizen");
winOrLose();
wincounter();
numberx--;
} else if (userinput == 2) { //when the user input is 2
if (computerinput == 1) {
System.out.println("you have played the citizen, this defeats the slave");
wincounter();
} else if (computerinput == 2) {
System.out.println("you have played the citizen, this ties with the citizen");
}
//print out something else if number is not 1,2 or 3
}
}

In this part, you've got the second if statement nested inside the first:
if (userinput == 1 && computerinput == 1 && cardLimiter == 0) {
System.out.println("you have played the emperor! \n the emperor is defeated by the slave");
cardLimiter++;
if ((userinput == 1 && computerinput == 1 && cardLimiter == 1)) {
System.out.println("you cannot play the emperor this turn \n you have played the citizen instead");
}
}
If userinput == 1 && computerinput == 1 && cardLimiter == 0 it will print out "you have played the emperor" etc. But then you immediately increment cardLimiter, so it will also print out "you cannot play the emperor this turn".
I imagine that's not the desired behavior, so I would recommend moving that second if statement out of the first one. Perhaps something like this:
if (userinput == 1 && computerinput == 1 && cardLimiter == 0) {
System.out.println("you have played the emperor! \n the emperor is defeated by the slave");
cardLimiter++;
} else if ((userinput == 1 && computerinput == 1 && cardLimiter == 1)) {
System.out.println("you cannot play the emperor this turn \n you have played the citizen instead");
}
That way, only one of the System.out.println statements will execute.

How would i prevent a user from duplicate entries (Using JOptionPane and if statements in this program)

So I'm currently writing a program that basically asks for user input and calculates total course load and fees based on that output.
I'm a bit stuck, however. I'm supposed to prevent the user from entering the same course number more than once and I can't seem to figure it out. Any help would be appreciated!
This is a small piece of my code:
while (option == JOptionPane.YES_OPTION) {
if (!(typeOfStudent.equals("Online") || typeOfStudent.equals("On campus"))) {
JOptionPane.showMessageDialog(null, "Enter either 'Online' or 'On campus'");
System.exit(0);
}
courseNumber = JOptionPane.showInputDialog("Enter the Course Number for the class you are taking(100/150/250/300): " + "\n");
courseNum = Integer.parseInt(courseNumber);
if (!(courseNum == 100 || courseNum == 150 || courseNum == 250 || courseNum == 300)) {
JOptionPane.showMessageDialog(null, "Enter a valid course number (100/150/250/300)");
System.exit(0);
}
if (courseNum == 100 && (typeOfStudent.equals("Online"))) {
totalNumCredits += credits100;
totalStudentFee += onlineStudentFee100;
}

Maintain a list of courses that are already selected by the user:
List<Integer> courses = new ArrayList<>();
Then modify your current code to check if the course is already selected or not.
if (!(courseNum == 100 || courseNum == 150 || courseNum == 250 || courseNum == 300)) {
JOptionPane.showMessageDialog(null, "Enter a valid course number (100/150/250/300)");
System.exit(0);
}
if(courses.contains(courseNum) {
JOptionPane.showMessageDialog(null, "It is an already selected course number");
return;
}
courses.add(courseNum);
if (courseNum == 100 && (typeOfStudent.equals("Online"))) {
totalNumCredits += credits100;
totalStudentFee += onlineStudentFee100;
}

Trouble calling one method into another

I have a program that deals with using different loops in different methods. The program as a whole is working fine apart from one method that calls another.
I am having trouble with a method that calls another.
What I want to do is:
Have the method call the other and run it which takes a variable
from the user (1 - 100).
Increment a variable if an invalid input is
entered.
Display a message and exit back to menu when 3 inputs are
entered in a row.
The method that is being called works fine on it's own and it works when I call it.
What I can't get to work is the display message when after 3 invalid inputs. At present, it takes about 7 invalid inputs then it displays the message??
Method that works:
public static boolean processGrade(int percentMark)
{
Menu m = new Menu();
clrscr();
System.out.println("Please enter your mark e.g. 90. (input -1 to exit): ");
percentMark = Genio.getInteger();
if
(percentMark >=70 && percentMark <=100)
{
clrscr();
System.out.println("Your Grade is A - Excellent!\n\n");
pressKey();
clrscr();
}
else if(percentMark >= 60 && percentMark <70)
{
clrscr();
System.out.println("Your Grade is B - Good!\n\n");
pressKey();
clrscr();
}
else if (percentMark >=50 && percentMark <60)
{
clrscr();
System.out.println("Your Grade is C - Ok!\n\n");
pressKey();
clrscr();
}
else if(percentMark >=40 && percentMark <50)
{
clrscr();
System.out.println(" Your Grade is D - Must Do Better!\n\n");
pressKey();
clrscr();
}
else if (percentMark <40 && percentMark >= 0 )
{
clrscr();
System.out.println(" Your Grade is E - Must Do Better!\n\n");
pressKey();
clrscr();
}
else if (percentMark < -1 || percentMark >100)
{
clrscr();
System.out.println("ERROR: Value MUST be in the range of 0 - 100!");
pressKey();
clrscr();
return false;
}
else if (percentMark == -1)
{
//clrscr();
System.out.println("You entered -1, you will now return to the menu!");
pressKey();
return false;
}
return true;
}
Method that I can't get to work that calls the above message:
public static void processGradeV2(int percentMark)
{
int invalid = 0;
outerloop:
do {
clrscr();
boolean result = processGrade(percentMark);
processGrade(percentMark);// Call processGrade method
if(result == false)
{
invalid++;
}
if(invalid == 3)
{
clrscr();
System.out.println("Sorry, you have entered an invalid integer 3 times in a row! The program will return to the menu screen.");
pressKey();
break outerloop;
//return;
}
if(percentMark == -1)
{
clrscr();
System.out.println("You entered -1, you will now return to the menu!");
pressKey();
clrscr();
break outerloop;
//processUserChoices();
}
}
while(invalid <3);
}

processGrade(percentMark);// Call processGrade method
will cause you a problem here, delete it.
You already assigned the processGrade(percentMark); result to the result variable.

I would delete boolean result = processGrade(percentMark) and instead change your if statement to:
if(!processGrade(percentMark)){
invalid++;
}

Repeating no matter my input

So the program that I am trying to write is something like this. The opponent picks a number at random where each number corresponding to a person. then the user does the same thing. then the out is to show what the user pick, what the opponent picked and who won that match. its similiar to rock, paper scissor but with some more stuff added to it. i also have to show the numbers of rounds played and how many times the user had won. But my problem is this. No matter what my input is, it keeps saying that i made an invalid choice and to pick it again. This is what I have.
public static void main(String[] args) {
int game=0;
int won = 0;
int opponent;
Random rand = new Random();
System.out.println("Welcome to the game. Here are the rules:");
Scanner in = new Scanner(System.in);
rules();
choices();
int choice = selected(in);
while (choice !=0) {
rules();
choices();
choice = selected(in);
opponent = opp();
result(choice, opponent, in);
game+=1;
}
System.out.println("You played " +game+" games.");
System.out.println("Quitting");
}
public static void rules(){
System.out.println("\nFlurg beats Stuga and Kvartal");
System.out.println("Stuga beats Kvartal");
System.out.println("Kvartal beats Lerberg");
System.out.println("Lerberg beats Flurg and Stuga");
System.out.println("The computer wins in the event of a tie.");
System.out.println();
}
public static int opp(){
Random rand = new Random();
int opponent = rand.nextInt(4)+1;
return opponent;
}
public static void choices(){
System.out.println("Please select your choice:");
System.out.println("'1' for Flurg ");
System.out.println("'2' for Stuga ");
System.out.println("'3' for Kvartal ");
System.out.println("'4' for Lerberg ");
System.out.println("'0' to Quit ");
System.out.print("Selection: ");
}
public static int selected(Scanner in){
int choice = in.nextInt();
while (choice != 1 && choice != 2 &&
choice != 3 && choice != 4 &&
choice != 0) {
System.out.println("Invalid choice");
choices();
choice = in.nextInt();
}
return choice;
}
public static int result(int choice, int opponent, Scanner in) {
int won=0;
System.out.print("You picked:" +choice+". Opponent picked:" +opponent+".");
if(choice == 1 && (opponent == 2) || (opponent == 3)){
System.out.println("You won!");
won+=1;
}
else if(choice == 2 && opponent == 3){
System.out.println("You won!");
won+=1;
}
else if(choice == 3 && opponent == 4){
System.out.println("You won!");
won=+1;
}
else if(choice == 4 && (opponent == 1 || opponent == 2)){
System.out.println("You won!");
won+=1;
}
else {
System.out.println("You lost!");
}
return won;
}
}
EDIT
So I fixed exactly what i was told about the !=1 part. but it is again looping. for some reason, it does not want to run result()
EDIT#2
Main also has been fixed with the similar problem.
EDIT#3
I have added more lines based on what I was told.

change this
choice != '1' && choice != '2' &&
choice != '3' && choice != '4' &&
choice != '0'
to this
choice != 1 && choice != 2 &&
choice != 3 && choice != 4 &&
choice != 0
What you were trying to do was int != char and the value for '1' in ASCII is 49 SO it was indeed not 1. You are reading int from the Scanner.

The problem is here
int choice = in.nextInt();
while (choice != '1' && choice != '2' &&
choice != '3' && choice != '4' &&
choice != '0') {
System.out.println("Invalid choice");
nextInt() will return the decimal value of an int type. (int)1 != (char)'1'. The easiest solution I can think of is
while (choice != 1 && choice != 2 &&
choice != 3 && choice != 4 &&
choice != 0) {

You are comparing the found values to chars.
int choice = in.nextInt();
while (choice != '1' //...
However, this compares the entered numerical value to the ASCII-code of the character which is 49 for the character '1'. Therefore, your loop will continue until you enter one of the numbers 48 ('0') to 52 ('4').
You should compare to the numbers instead:
while (choice != 1 && choice != 2 && choice != 3 && choice != 4 && choice != 0) {
System.out.println("Invalid choice");
}
The same goes for
while (choice !='0') {
rules();
choices();
selected(in);
opp();
result(choice, opponent, in);
}
in your main method -- change this to
while (choice != 0) { // change this to 0 instead of '0'
rules();
choices();
choice = selected(in); // assign the value to choice
opponent = opp(); // assign the value to opponent
result(choice, opponent, in);
}
You also did not assign the return values of the methods to the local variables -- they are never going to change and the loop will never end like that!

Java homework help

I have this assignment that I've tried. But when I enter 1 it should not give any output as 1 is > 0 and 1 is not even but I still get output as:
Enter a +ve number
1
You entered 1
I'd asked for a +ve number :)
.
import java.util.Scanner;
class Main {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter a +ve number");
int number = input.nextInt();
System.out.println("You entered "+number);
if(number > 0)
if(number %2 == 0)
System.out.println("Number"+number+" is even and +ve");
else
System.out.println("I'd asked for a +ve number :)");
}
}

Your else actually belongs to the 2nd if not the 1st if as the indentation shows.
if(cond1)
if(cond2)
else // this else belongs to 2nd if not 1st if.
is same as:
if(cond1) {
if(cond2) {
} else {
}
}
This is because the Java grammar says that an else belongs to the closest unmatched if to which it can possibly belong.
If you want to match the else with first if you need to use parenthesis as:
if(cond1) {
if(cond2) {
}
} else {
}

Check that the code actually follows the logic it ought to - indentation won't help you with flow control, that's what curly brackets {} are for.

That would probably be because your ifs are interpreted like this:
if(number > 0)
if(number %2 == 0)
System.out.println("Number"+number+" is even and +ve");
else
System.out.println("I'd asked for a +ve number :)");
How's the computer supposed to know what you mean? You need to use brackets to make it unambiguous:
if(number > 0) {
if(number %2 == 0) {
System.out.println("Number"+number+" is even and +ve");
}
} else {
System.out.println("I'd asked for a +ve number :)");
}

I get the following output when I enter 1:
Enter a +ve number
1
You entered 1
I'd asked for a +ve number :)
Which is reasonable as you first check
if (number > 0)
which is true for number == 1 and then you check
if (number % 2 == 0)
which is false for number == 1 thus the else branch is taken:
System.out.println("I'd asked for a +ve number :)")
Your code should probably look something like:
Scanner input = new Scanner(System.in);
System.out.println("Enter a +ve number");
int number = input.nextInt();
System.out.println("You entered " + number);
if (number > 0) {
if (number % 2 == 0)
System.out.println("Number" + number + " is even and +ve");
} else {
System.out.println("I'd asked for a +ve number :)");
}

first you should try to debug (using eclipse maybe)
add paranthesis after if(number > 0) statement to wrap inner if statement.

I threw your code into Netbeans and had it auto format it for readability. Is this your intended logic flow? Because this is how the compiler sees your if statements alignment/nesting.
import java.util.Scanner;
public class Main
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
System.out.println("Enter a +ve number");
int number = input.nextInt();
System.out.println("You entered " + number);
if (number > 0)
{
if (number % 2 == 0)
{
System.out.println("Number" + number + " is even and +ve");
}
else
{
System.out.println("I'd asked for a +ve number :)");
}
}
}
}

1 %2 == 1 so it's clear that it enters on the else branch

its because your else statement is saying if its not even then say "i asked for a +ve number"
move it out of the if statement like this
if(number > 0)
{
if(number %2 == 0)
{
System.out.println("Number"+number+" is even and +ve");
}
}
else
{
System.out.println("I'd asked for a +ve number :)");
}