How to access elements from multi-dimensional array in C#?

To access elements from a multi-dimensional array in C#, you specify indices for each dimension using square brackets with comma-separated values. For example, a[2,1] accesses the element at row 3, column 2 (using zero-based indexing).

Syntax

Following is the syntax for accessing elements from a multi-dimensional array −

arrayName[index1, index2, ...indexN]

For a 2D array, you use two indices −

int element = array[rowIndex, columnIndex];

Understanding Array Indexing

Multi-dimensional arrays use zero-based indexing, meaning the first element is at index [0,0]. Consider this 4×2 array structure −

Example

The following example demonstrates how to access elements from a 2D array −

using System;

namespace Program {
   class Demo {
      static void Main(string[] args) {
         int[,] a = new int[4, 2] {{0,0}, {1,2}, {2,4}, {3,6} };
         int i, j;

         Console.WriteLine("All elements in the array:");
         for (i = 0; i < 4; i++) {
            for (j = 0; j < 2; j++) {
               Console.WriteLine("a[{0},{1}] = {2}", i, j, a[i,j]);
            }
         }

         Console.WriteLine("\nAccessing specific elements:");
         Console.WriteLine("Element at [2,1]: " + a[2,1]);
         Console.WriteLine("Element at [0,0]: " + a[0,0]);
         Console.WriteLine("Element at [3,1]: " + a[3,1]);
      }
   }
}

The output of the above code is −

All elements in the array:
a[0,0] = 0
a[0,1] = 0
a[1,0] = 1
a[1,1] = 2
a[2,0] = 2
a[2,1] = 4
a[3,0] = 3
a[3,1] = 6

Accessing specific elements:
Element at [2,1]: 4
Element at [0,0]: 0
Element at [3,1]: 6

Accessing 3D Array Elements

For arrays with more dimensions, you simply add more indices −

using System;

class Program {
   static void Main() {
      int[,,] cube = new int[2, 2, 2] {
         {{1, 2}, {3, 4}},
         {{5, 6}, {7, 8}}
      };

      Console.WriteLine("3D Array Elements:");
      Console.WriteLine("cube[0,0,0] = " + cube[0,0,0]);
      Console.WriteLine("cube[0,1,1] = " + cube[0,1,1]);
      Console.WriteLine("cube[1,0,1] = " + cube[1,0,1]);
      Console.WriteLine("cube[1,1,0] = " + cube[1,1,0]);
   }
}

The output of the above code is −

3D Array Elements:
cube[0,0,0] = 1
cube[0,1,1] = 4
cube[1,0,1] = 6
cube[1,1,0] = 7

Conclusion

Accessing multi-dimensional array elements in C# requires specifying indices for each dimension using comma-separated values within square brackets. Remember that arrays use zero-based indexing, so the first element is at [0,0] for 2D arrays or [0,0,0] for 3D arrays.