Print even and odd level nodes in binary tree in node js

Js program for Print even and odd level nodes in binary tree. Here mentioned other language solution.

/* 
  Node JS program for
  Print the nodes of even and odd levels of binary tree
*/
// Binary Tree node
class TreeNode
{
	constructor(data)
	{
		// Set node value
		this.data = data;
		this.left = null;
		this.right = null;
	}
}
class BinaryTree
{
	constructor()
	{
		this.root = null;
	}
	// Print all nodes which is exist in odd Level
	oddLevel(node, level)
	{
		if (node != null)
		{
			if (level % 2 != 0)
			{
				// Display even odd node value
				process.stdout.write(" " + node.data);
			}
			this.oddLevel(node.left, level + 1);
			this.oddLevel(node.right, level + 1);
		}
	}
	// Print all nodes which is exist in even Level
	evenLevel(node, level)
	{
		if (node != null)
		{
			if (level % 2 == 0)
			{
				// Display even level node value
				process.stdout.write(" " + node.data);
			}
			this.evenLevel(node.left, level + 1);
			this.evenLevel(node.right, level + 1);
		}
	}
}

function main()
{
	// Create new tree
	var tree = new BinaryTree();
	/*
	    Binary Tree
	    -------------
	        10
	       /  \
	      2    4
	     /    / \
	    3    6   5
	     \    \
	      9    7
	            \
	             11       
	*/
	// Add tree nodes
	tree.root = new TreeNode(10);
	tree.root.left = new TreeNode(2);
	tree.root.left.left = new TreeNode(3);
	tree.root.left.left.right = new TreeNode(9);
	tree.root.right = new TreeNode(4);
	tree.root.right.right = new TreeNode(5);
	tree.root.right.left = new TreeNode(6);
	tree.root.right.left.right = new TreeNode(7);
	tree.root.right.left.right.right = new TreeNode(11);
	process.stdout.write("\n Even Level Nodes : ");
	tree.evenLevel(tree.root, 1);
	process.stdout.write("\n Odd Level Nodes  : ");
	tree.oddLevel(tree.root, 1);
}
// Start program execution
main();

Output

 Even Level Nodes :  2 9 4 7
 Odd Level Nodes  :  10 3 6 11 5