Thread: Two dimensional arrays - HELP!

Hi!I'm ecco, and I'm pretty new at these forums (obviously), and I need some help with one of my Java-programs.

My program is based on commands through user input (1-7), for buying oil-fields (in Utiopia), showing lists, overviews etc (the rest is not really that important). Command 1 asks the user to give the companies name, and what fields he wants to buy, and depending on whether the fields are bought or not already, I want to save this data into 2 different two-dimensional arrays (one for the company-name, one for fields(rows-columns).

Row-input should only be between the numbers 0 and 10, while columns-input need to be between 0 and 15. The program compiles and runs just fine, but my problem lies at my column-input;

Whenever i set the column-number to be 10 or more, i get an ArrayIndexOutOfBoundsExceptionError, and I believe my problem lies in my for-loops, though, I can't seem to find it. I've been trying to get this to work for hours! Here's my code (read between the 'HERE' and 'to HERE'-commentaries, line 75-85, marked in bold):

 
import easyIO.*;
 
class oilAdmin {
 
 
    public static void main(String[] args) {
        System.out.println("*** Utiopias oil-administration ***");
        Oil oil = new Oil();
        oil.commandLoop();
        System.out.println("--- Ending program! ---");
    }
}
 
 
    class Oil {
        In key = new In();
        Out screen = new Out();
 
        // In-objects
        In inName = new In();
        In row = new In();
        In col = new In();
 
        // Two-dimensional arrays
        String [][] owner = new String[10][15];
        int [][] field = new int[10][15];
 
        // Command -> method
        void commandLoop() {
            int command = -1;
 
            while (command != 0) {
 
			String menu = "1. Buy field \n" +
                               "2. List fields \n" +
				                   "3. Overview w/statistics \n" +
       	        	                   "4. Update oil-fields \n" +
							               "5. Find row with MAX oil \n" +
							                   "6. Quit \n";
 
			System.out.println(menu);
 
            System.out.print("Give command: ");
            command = key.inInt();
 
            switch (command) {
                    case 1: buyField(); break;
                    case 2: showList(); break;
                    case 3: showOverview(); break;
                    case 4: updateOil(); break;
                    case 5: maxOil(); break;
                    case 6: exit(); break;
                }
            }
 
        }
 
 
        void buyField() {
 
			Oil oil = new Oil();
 
           // Name of buyer
            System.out.print("Name of buyer: ");
            String name = inName.inWord();
 
            // Fields
            System.out.print("Oil-field (1) required (ROW, 0-10): ");
            int rowNum = row.inInt();
            System.out.print("Oil-field (2) required (COL, 0-15): ");
            int colNum = col.inInt();
 
 
			[B]// HERE
			if ( rowNum <= 10 && rowNum >= 0 && colNum <= 15 && colNum >= 0 && owner[colNum][rowNum] == null && owner[rowNum][colNum] == null) {
				for (int i=0; i<field.length; i++) {
					for (int j=0; j<field[i].length; j++) {
						field[colNum][rowNum] = rowNum;
						field[rowNum][colNum] = colNum;
						owner[rowNum][colNum] = name;
						owner[colNum][rowNum] = name;
					}
				}
			}
			// to HERE.[/B]
 
			else {
				System.out.println("Invalid input. Try again!");
				oil.commandLoop();
			}
 
			System.out.println("Field bought! " + owner[colNum][rowNum] + " now have full rights at: " + field[colNum][rowNum] + "-" + field[rowNum][colNum]);
 
        }
 
        void showList() {
 
        }
 
        void showOverview() {
 
        }
 
        void updateOil() {
 
        }
 
        void maxOil() {
 
        }
 
        void exit() {
            System.exit(1);
        }
 
 
 
    }

I'm open to all suggestions. Thanks in advance
ecco

Your code isn't consistent in its use of indexes:
field[colNum][rowNum] = rowNum; // col then row
field[rowNum][colNum] = colNum; // row then col

Can you explain what these lines of code are supposed to do?

Originally Posted by Norm

Your code isn't consistent in its use of indexes:
field[colNum][rowNum] = rowNum; // col then row
field[rowNum][colNum] = colNum; // row then col

Can you explain what these lines of code are supposed to do?

Yeah, thing is I want the row-values to be in the first dimension of the array, and the column-values to be in the second. Obviously, this is where my problem is, but writing;

 field[rowNum] = rowNum;

.. inside the first of the two for-loops, gives me a type-error (found:int, required:int[]). I might not have explained it perfectly good enough, so I'll try again with an example;

Let's say our user tells us his company name is JavaOil, and JavaOil wants to buy the oil in fields of 9(rows)-12(columns). This is where that part you're mentioning comes in; i want the value of rowNum to go into the first dimension of the field-array, at the position equalled to rowNum, and the value of colNum to go into the second dimension of the same array, at the position equalled to colNum - from there, I can connect this data to the owner, JavaOil, which should be placed in the owner-array at its places equalled to the values of rows and columns in my field-array.

Hope that made things more clear of what I'm trying to do. Long story short i want the user input of rows and columns to go into the position thats equal to the key in the array(in its correct dimension).

If you are going to use the same indexes in both dimensions of the array, you should define the two dimensions of the array to be the same size:
int [][] field = new int[15][15];

Made it work. Thanks, Norm!