i m getting an error while using array, please help me

somasekhara777

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace multiplication
{
class Program
{
static void Main(string[] args)
{
int[,] a = new int[2, 2] { { 1, 2 }, { 3, 4 } };
int[,] b = new int[2, 2] { { 1, 2 }, { 3, 4 } };
int[,] c = new int[2, 2];
for (int i = 0; i <= a.Length; i++)
{
for (int j = 0; j <= b.Length; j++)
{
c[i, j] = (a[i, j] * b[i, j])+(a[i,,j+1]*b[i+1,,j]);
Console.Write(c[i, j]+ " " );

            }
            Console.WriteLine();
        }
            Console.ReadLine();

    }
}

}
erorr is like
Index was outside the bounds of the array.

j somasekhar

Lost User

Please include the error-text, and the result that you were aiming for - ie, what should the code do?

Bastard Programmer from Hell :suss: if you can't read my code, try converting it here[^]

Pete OHanlon

For those who can't read minds, the exception you are getting is an out of bounds exception. The area that you are hitting this exception is here:

(a[i, j + 1] * b[i + 1, j])

The reason you are hitting this is because j+1 is 2 after the first iteration of j, which is outside of the bounds of the array. As I'm not sure what effect you are aiming at here, I can't really offer any concrete solution other than to say that you need to think through your logic here. BTW - what length do you think is represented as a.Length or b.Length. It's not the 2 you're expecting; it's 4. Also, you are using <= in your conditions and it should be < only.

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"Mind bleach! Send me mind bleach!" - Nagy Vilmos

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markovl

At first glance, there's a syntax error here (...) (a[i,,j+1]*b[i+1,,j]) (...) - note the consecutive commas, lose one of each. Like this:

// omitted
c[i, j] = (a[i, j] * b[i, j])+(a[i,j+1]*b[i+1,j]);
// omitted

2A

markovl

Nice catch! Have a five. After spotting the syntax error in the code sample, I directly assumed that was the problem and stopped thinking right there... :)

2A

Pete OHanlon

I spotted that error and figured it was just an error putting it into the CP editor. As soon as I saw that it was arrays and looping, I knew he'd have an out of bounds error in there somewhere. The rest was just figuring out where it was.

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Luc Pattyn

If that is meant to perform a matrix multiplication, then: 1. it would require 3 nested loops, not 2, as each element (that is 2 loops) of the result matrix is to equal the inner product of one row and one column (that is the third loop, dealing with both the row of a and the column of b) 2. I would not waste time on doing a specific case; instead use variable dimensions to make it general-purpose. 3. And unless you want this as an exercise, there is a Matrix class that does it all for you, no hassle. See e.g. here[^] :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Luc Pattyn

. If that is meant to perform a matrix multiplication, then: 1. it would require 3 nested loops, not 2, as each element (that is 2 loops) of the result matrix is to equal the inner product of one row and one column (that is the third loop, dealing with both the row of a and the column of b) 2. I would not waste time on doing a specific case; instead use variable dimensions to make it general-purpose. 3. And unless you want this as an exercise, there is a Matrix class that does it all for you, no hassle. See e.g. here[^] :)

Luc Pattyn [My Articles] Nil Volentibus Arduum