Spiral traversal of matrix in node js

Js program for Spiral traversal of matrix. Here more information.

// Node JS program for 
// Spiral form of matrix
class SpiralView
{
	spiral(data, startRow, startCol, endRow, endCol, element)
	{
		// Left to right
		for (var i = startCol; i <= endCol && element > 0; ++i)
		{
			element--;
			process.stdout.write("  " + data[startRow][i]);
		}
		// Top to down
		for (var i = startRow + 1; i <= endRow && element > 0; ++i)
		{
			element--;
			process.stdout.write("  " + data[i][endCol]);
		}
		// Bottom right to bottom-left
		for (var i = endCol - 1; i >= startCol && element > 0; --i)
		{
			element--;
			process.stdout.write("  " + data[endRow][i]);
		}
		// Bottom left to top
		for (var i = endRow - 1; i > startRow && element > 0; --i)
		{
			element--;
			process.stdout.write("  " + data[i][startRow]);
		}
		if (startRow + 1 <= endRow - 1 && element > 0)
		{
			// Recursive call
			this.spiral(data, startRow + 1, 
                        startCol + 1, endRow - 1, 
                        endCol - 1, element);
		}
	}
}

function main()
{
	var task = new SpiralView();
	// Given matrix
	var matrix = [
		[1, 2, 3, 4, 5, 6],
		[22, 23, 24, 25, 26, 7],
		[21, 36, 37, 38, 27, 8],
		[20, 35, 42, 39, 28, 9],
		[19, 34, 41, 40, 29, 10],
		[18, 33, 32, 31, 30, 11],
		[17, 16, 15, 14, 13, 12]
	];
	var row = matrix.length;
	var col = matrix[0].length;
	// Get the number of element
	var element = row * col;
	task.spiral(matrix, 0, 0, row - 1, col - 1, element);
}
// Start program execution
main();

Output

  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38  39  40  41  42