Converting index of one dimensional array into two dimensional array i. e. row and column

Question

I have one application of WinForms which inside list box I am inserting name and price..name and price are stored in two dimensional array respectively. Now when I select one record from the listbox it gives me only one index from which I can get the string name and price to update that record I have to change name and price at that index for this I want to update both two dimensional array name and price. but the selected index is only one dimensional. I want to convert that index into row and column. How to do that?

But I'm inserting record in list box like this.

int row = 6, column = 10;
for(int i=0;i<row;i++)
{
    for(int j=0;j<column;j++)
    {
        value= row+" \t "+ column +" \t "+ name[i, j]+" \t " +price[i, j];
        listbox.items.add(value);
    }
}

You should probably post some code.... – DotNetRussell May 28 '13 at 11:16 — DotNetRussell, May 28 '13 at 11:16

BambooleanLogic · Accepted Answer · 2013-12-02T08:22:11.847

42

While I didn't fully understand the exact scenario, the common way to translate between 1D and 2D coordinates is:

From 2D to 1D:

index = x + (y * width)

or

index = y + (x * height)

depending on whether you read from left to right or top to bottom.

From 1D to 2D:

x = index % width
y = index / width

or

x = index / height
y = index % height

edited Dec 02 '13 at 08:22

answered May 28 '13 at 11:19

BambooleanLogic

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How to do it for multidimensional arrays? – Vlad Mar 07 '16 at 14:50

score 0 · Answer 2 · answered May 28 '13 at 11:17

0

Try this,

int i = OneDimensionIndex%NbColumn
int j = OneDimensionIndex/NbRow //Care here you have to take the integer part

answered May 28 '13 at 11:17

Leep

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This is correct if the source array contains a sequence like `name price name price ...`. This, however, is not a real two-dimensional array. – Thorsten Dittmar May 28 '13 at 11:18

score 0 · Answer 3 · answered May 28 '13 at 11:17

Well, if I understand you correctly, in your case, obviously the index of the ListBox entry's array entry is the index in the ListBox. The name and price are then at index 0 and index 1 of that array element.

Example:

string[][] namesAndPrices = ...;

// To fill the list with entries like "Name: 123.45"
foreach (string[] nameAndPrice in namesAndPrices)
   listBox1.Items.Add(String.Format("{0}: {1}", nameAndPrice[0], nameAndPrice[1]));

// To get the array and the name and price, it's enough to use the index
string[] selectedArray = namesAndPrices[listBox1.SelectedIndex];
string theName = selectedArray[0];
string thePrice = selectedArray[1];

If you have an array like that:

string[] namesAndPrices = new string[] { "Hello", "123", "World", "234" };

Things are different. In that case, the indices are

int indexOfName = listBox1.SelectedIndex * 2;
int indexOfPrice = listBox1.SelectedIndex * 2 + 1;

How about changing the question adding relevant parts of your source code? This is *not* something to be posted in the comments. — Thorsten Dittmar, May 28 '13 at 11:28

Converting index of one dimensional array into two dimensional array i. e. row and column

3 Answers3

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