Multi-Dimensional Arrays

Overview

Multi-dimensional arrays are arrays of arrays. A 2D array represents a matrix or grid, which is incredibly useful for rendering maps, boards, or mathematical computations.

Syntax

cpp

// 2D Array: Type name[rows][cols]
int matrix[2][3] = {
    {1, 2, 3}, // Row 0
    {4, 5, 6}  // Row 1
};

// Accessing elements
int val = matrix[1][2]; // 6

Common Pitfalls

Confusing row and column indices (`matrix[col][row]` instead of `matrix[row][col]`).

Interview Tips

When passing a 2D array to a function, you MUST specify the number of columns in the parameter: `void printMatrix(int mat[][3], int rows)`.

Real-World Example

Iterating through a 2D grid.

example

cpp

#include <iostream>
using namespace std;

int main() {
    int grid[3][3] = {
        {1, 2, 3},
        {4, 5, 6},
        {7, 8, 9}
    };
    
    for (int row = 0; row < 3; row++) {
        for (int col = 0; col < 3; col++) {
            cout << grid[row][col] << " ";
        }
        cout << "\n";
    }
    return 0;
}

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