Java iterate through 1D array and 2D array

Question

I have a 1d array of questions and a 2d array of answers. I'm trying to print off one question and the multiple choice answers for that question and get user input then go back and get the second question and print off the multiple choice answers from the 2d array. Sorry if confusing. Code:

private String[] questions =
{"Favourite Sweet", "Favourite subject at Hogwarts", "Dream Vacation"};

private String [][] selection =

{{"1.Acid Pops","2.Sherbert Lemons","3.Bertie Bott's Every Flavour Beans",
"4.Cake","5.Hagrid's Rock Cakes","6.Chocolate Frogs","7.Ginger Newt",
"8.I hate sweets\n"},

{"1.Care of Magical Creatures","2.Charms","3.Defense Against the Dark Arts", 
"4.Divination","5.Herbology","6.History of Magic","7.Muggle 
Studies","8.Potions", "9.Study of Ancient Runes","10.Transfiguration\n"},

{"1.Anywhere with friends","2.Egypt","3.Hogwarts","4.Museum","5.India","6.Forest",
"7.Can't be bothered with a vacation\n"}

};

I want to print off "Favourite Sweet" and then 1-8 sweets then print "Favourite subject at Hogwarts" then 1-10 subjects then "Dream Vacation" and print 1-7 vacations.

Code I have is garbage but here it is:

public void printQuestion(){


    for (rowQ = 0; rowQ <= questions.length; rowQ++){
        System.out.println(questions[rowQ]);
        for(int rowS = rowQ; rowS <= rowS; rowS++){
            for(int colS = rowS; colS <= selection[rowS].length; colS++){
            System.out.println(selection[rowS][colS]);

        }
    }
}

This is what happening with my code now when I run it:

Favourite sweet

1.Acid Pops

2.Sherbert Lemons

3.Bertie Bott's Every Flavour Beans

4.Cake

5.Hagrid's Rock Cakes

6.Chocolate Frogs

7.Ginger Newt

8.I hate sweets

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 8

What's happening currently? What specific issue are you having? What steps have you taken to debug/reason about the problem? What is the problem? — Dave Newton
– Dave Newton, Commented Feb 24, 2018 at 21:54
Your iterations stop at rowQ == question.length and you are getting out-of-bounds exception. All your iterations. Change iteration check from <= to < at it should work. And of course fix that infinite loop at rowS <= rowS — Random Guy
– Random Guy, Commented Feb 24, 2018 at 22:00
you are confusing how rows and column indicies work on line 3 and 4. — user7502825
– user7502825, Commented Feb 24, 2018 at 22:00
Valid array indices are 0 to array.length - 1 - lose the = in rowQ <= questions.length and rowS <= rowS is an infinite loop. And lose the = in all of those tests. — Elliott Frisch
– Elliott Frisch, Commented Feb 24, 2018 at 22:01

Tomer · Accepted Answer · 2018-02-24 22:10:33Z

2

Since you said that your code is not good I took the privilege of rewriting it completely and it works for me:

for (int i = 0 ; i < questions.length ; i++){
    System.out.println(questions[i]);
    for(int j = 0 ; j  < selection[i].length ; j++){
        System.out.println(selection[i][j]);
    }
}

The Idea behind this is for every question print out all the answers in the selection array that has the same index as the question array up to the end of that array

answered Feb 24, 2018 at 22:10

Tomer

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3 Comments

LLgood Over a year ago

Thanks so much that works perfect!!!! So selection[i].length is how it prints to the end of that index corresponding to the question? if that makes sense.

Tomer Over a year ago

Yep selection[I].length corresponse with the question and the length of all the answer/selections

Tomer Over a year ago

By the way if the answer answers your question it will be good for the community to sign my answer as a solution. (Also it will be great for me :-) since it highers my rating)

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