how to code a for loop using a 2 dimensional array

Question

I am just learning java and while completing an assignment i ran into a problem. I need to use the for loop but I'm unsure of the proper coding. I was able to compile my code to get the output for the 1st challenge but i am unable to do so for the remaining challenges. Any suggestions/tips are greatly appreciated.

/Your instructor is in a bind.  His place of work has instituted a new 
//technology project that will require remote access verification. 
//In addition to his user name and password, he will have a “challenge” 
//to each sign-on. That challenge will require that he input a number or 
//letter depending on what the security application asks him.
//But your instructor is lazy. He wants an application that will 
//tell him what those appropriate numbers are without him having to 
//look them up each time.  He understands that this will help foil 
//remote hackers, but he does not want to be stuck carrying around a piece of paper all the time.

//Write your instructor a program that gives him the three characters asked for.  The matrix to use is:
//A B C D E F G H I J 
//1 3 N 1 M 4 R X 5 F N
//2 N V T 5 K Q F M 3 P
//3 9 K 1 Y R 4 V T F 3
//4 3 3 9 V 4 Y R T N N
//5 3 1 1 3 2 9 X P N P

//A challenge of A1:B2:C3 would yield 3 V 1.
//A challenge of G4:D2:J3 would yield R 5 3.

// 1. Create a place to accept input
            //  ---- create a scanner class
            // 2. ask for input  
            String  input = "a1";


            // 3. Take the first character from the challenge
            //      (like "D2" would "D" and find its analogous int array value)

            int i1 = Util.findFirstValue(input);
            System.out.println(i1);

            // 4.Take the second character from the challenge (like "D2"
            //      would be "2") and find its analogous int array value
            //      Hint: always one less than the value entered.
            int i2 = Util.findSecondValue(input);
            System.out.println(i2);

            // 5. inquire with the array with the challenge values to get the desired value

            System.out.println(Util.findArrayValue(i1, i2));

            // 6. display the value 
            // 7. repeat twice more steps 2 through 6
        }


        {   
        for (int row =1; row<9;row ++) {
        for (int column =2; column <5;column ++) {

What's your question?

Spencer Wieczorek
– Spencer Wieczorek

2014-07-25 04:23:59 +00:00
Commented Jul 25, 2014 at 4:23 — Spencer Wieczorek
– Spencer Wieczorek, Commented Jul 25, 2014 at 4:23
a lot of lost brackets

Jay Harris
– Jay Harris

2014-07-25 04:24:08 +00:00
Commented Jul 25, 2014 at 4:24 — Jay Harris
– Jay Harris, Commented Jul 25, 2014 at 4:24
You really don't know how to ask a question mate !!

Gurucharan Balakuntla Maheshku
– Gurucharan Balakuntla Maheshku

2014-07-25 04:34:27 +00:00
Commented Jul 25, 2014 at 4:34 — Gurucharan Balakuntla Maheshku
– Gurucharan Balakuntla Maheshku, Commented Jul 25, 2014 at 4:34

Community · Accepted Answer · 2017-05-23 10:33:31Z

0

For looping through multi dimensional arrays it must like this

for(int i=0; i<multiarray[i].length; i++) {
multiarray[i][k]; //do something with it!
}

You can find heree about iterating multi dimensiona array in java.

edited May 23, 2017 at 10:33

CommunityBot

11 silver badge

answered Jul 25, 2014 at 4:33

Avinash Babu

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Comments

Spencer Wieczorek · Accepted Answer · 2014-07-25 04:46:30Z

0

Think of a 2D array like a table. The first for loop to get a row from that table, then the next for loop gets a certain element from that row (column).

1, 2, 3
4, 5, 6     -->        4, 5, 6       -->         6
7, 8, 9   array[1]               array[1][2]

So basically. The first loop gets the basic array within the 2D array, the next gets that exact value in that basic array.

Code:

int[][] A = { {1,2,3},
              {4,5,6},
              {7,8,9} };

for(int i = 0; A.length>i; i++) {
    for(int j = 0; A[0].length>j; j++) {
        System.out.println(A[i][j]);
    }
}

Output:

answered Jul 25, 2014 at 4:46

Spencer Wieczorek

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