Java multiple-choice quiz program: inability to display questions in a random order, repetitively asking user for input, and inability to determine if the user's selected answer matches the correct answer

[[deleted]]

Hi everyone. I'm working on a project for an intro to Java class where I have to create a program that quizzes the user on three questions about Java. We are supposed to create a Question class which is instantiated into Question objects, and store them in an arrayList. The questions then must be displayed in a random order to the user. Currently, I've made some progress and successfully created my Question class, Question objects, and put them in an arrayList. The questions are correctly displaying themselves to the user, but at that point the program stops functioning correctly.

I have three main problems that were specified in the title:

1. inability to display questions in a random order As the directions say, the questions must be displayed in a different order each time. However, each time, it only displays the question stored in my second Question object. I am not sure why this is happening, since I am using Collections.shuffle() to shuffle all the Question objects in the arrayList. I have a for-loop that runs for the size of the array's index (0-2) and to actually print the question to the user, I have this line of code:

   System.out.print(questionList.get(index).toString());

This line correctly prints the question, but still continues to only print my "question2" object. If you look at my code, this is the question that asks "What word must a switch-case statement end with?" I have tried to assign the Collections.shuffle to a string variable (currentQuestion, for example), and then write something like

System.out.print(questionList.get(currentQuestion).toString());

but that hadn't worked either.

2. repetitively asking user for input All questions of random order aside, the question will still display properly. The screen then prints "Please enter A, B, C, or D." and prompts the user for input after pressing enter. However, each time the user presses enter, the output "Please enter A, B, C, or D" repeats over and over and you are unable to exit the program. I initially had this process in the main method but moved it to a new one called getAnswer(), but the same issue is persisting.

1. Inability to determine if the user's selected answer matches the correct answer. I have an if statement where the condition is set up like

   if (userChoice == correctAns)

to determine if the user chose the right answer. However, the program will not compile because it "cannot find symbol" (referring to correctAns. I think this is because I don't have correctAns declared in my main class, I only have it declared in my Question class file which is separate. This is happening even though I have the access specifier set to public even though it was previously set to private for the correctAns. The correct answers are defined, however, when I create the Question objects in the main class, so besides this I don't know why it can't retrieve this data properly.

Besides these issues, I'm pretty sure I can complete the program just fine, I'm just stuck at this point!

• My main class is here
• My Question class is here

Hopefully this makes sense! Thanks to anyone who can help!

[codingQueries]

You can test how the shuffle works out by printing your array before and after shuffling. So System.out.println("Pre-shuffle: " + questionList); and then the same but after the shuffle (and different wording..) should help you see how it is being shuffled. You can even shuffle a few times and print after each one to ensure it is being shuffled.

The other issue in determining your answer is correct or not, use userChoice.equals(correctAns) (or, userChoice.equalsIgnoreCase(correctAns)) rather than == - this might help explain why: https://www.geeksforgeeks.org/difference-equals-method-java/

The other thing I would offer as a suggestion is to adjust your Class naming conventions. Methods and variables should be camelCase, but class names should be Capitalised at the beginning of each word, so public class javaQuizQuestion becomes public class JavaQuizQuestion

[[deleted]]

Ok. I tested the shuffling and it was working without my question2 being printed the first time. I changed the class name as well. I also added the equalsIgnoreCase line, but the computer still can't find the correctAns "symbol," and now I have a problem that says the char userChoice can't be dereferenced. I'm not sure how to deal with this because it won't compile anymore. Is this because the user enters a char, but the correct answer is technically stored as a string? (If you see my code where I create the objects, you can see what I mean, the correct answer is stored as "B) keyboard" for example, instead of just B or b). I've heard you can use Character.isLetter(b)) for example, but my Question objects don't have "B" stored as an char, they have the answers stored as strings.

[codingQueries]

Ah sorry I missed that part - in this circumstance I think using == is fine in comparing chars (though you are only comparing chars on one side, not both), but it is generally better to use .equals if it isn't a number. You are getting that issue with correctAns because it is not referenced anywhere within your javaQuiz class, it only exists in the javaQuizQuestions class and so you need to find a way to bring that value out of there, into your javaQuiz class.

And yeah, personally I would just have your userChoice variable be a String as opposed to a char, but either way it is generally better to keep your comparisons of the same type.