Interchange the diagonal of a matrix in node js

Js program for Interchange the diagonal of a matrix. Here mentioned other language solution.

/*
  Node JS program for
  Swap diagonal elements of matrix using recursion
*/
// Method which are perform swap operation
// Here x and y indicate start and end rows
// p and q indicates start and end columns
function swapDiagonal(matrix, x, y, p, q)
{
	if (x >= y || p >= q)
	{
		return;
	}
	var temp = matrix[x][p];
	// Swap the element value
	matrix[x][p] = matrix[x][q];
	matrix[x][q] = temp;
	temp = matrix[y][p];
	// Swap the element value
	matrix[y][p] = matrix[y][q];
	matrix[y][q] = temp;
	swapDiagonal(matrix, x + 1, y - 1, p + 1, q - 1);
}
// Display matrix elements
function showMatrix(matrix, size)
{
	
	console.log(matrix);
}

function main()
{
	// Define matrix element
	var matrix = [
		[1, 2, 3, 4],
		[5, 6, 7, 8],
		[9, 10, 11, 12],
		[13, 14, 15, 16]
	];
	// Assume N X N matrix
	var n = matrix.length;
	// Display element
	showMatrix(matrix, n);
	// interchange request
	swapDiagonal(matrix, 0, n - 1, 0, n - 1);
	// Display element
	showMatrix(matrix, n);
}
// Start program execution
main();

Output

[ [ 1, 2, 3, 4 ],
  [ 5, 6, 7, 8 ],
  [ 9, 10, 11, 12 ],
  [ 13, 14, 15, 16 ] ]
[ [ 4, 2, 3, 1 ],
  [ 5, 7, 6, 8 ],
  [ 9, 11, 10, 12 ],
  [ 16, 14, 15, 13 ] ]