Multidimensional Arrays

JavaScript does not have built‑in multidimensional arrays, but you can create arrays of arrays. These are often used for matrices, grids, or nested data structures. Access elements using multiple indices.

Key Points

• Arrays are not true multidimensional; they are nested.
• Can be jagged (sub‑arrays can have different lengths).
• Use nested loops to iterate.

Code Example

// 2D array (3x3 matrix)
const matrix = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9],
];

console.log(matrix[1][2]); // 6

// Jagged array
const jagged = [[1, 2], [3, 4, 5], [6]];

// Iteration
for (let i = 0; i < matrix.length; i++) {
  for (let j = 0; j < matrix[i].length; j++) {
    console.log(matrix[i][j]);
  }
}

// Using forEach
matrix.forEach((row) => {
  row.forEach((cell) => console.log(cell));
});