How to implement Post Order Traversal of Binary Tree in Java - Recursion and Iteration Example

This is the third article on tree traversal. In the last couple of articles, I have shown you how to implement preorder and inorder traversal in Java, both recursively and iteratively and today, you will learn about the post-order traversal. Out of these three main tree traversal algorithms, the post-order traversal is most difficult to implement, especially the iterative version. In postorder traversal, you first visit left subtree, then right subtree and at last you print the value of root or not. So, the value of root is always printed at last in the post-order traversal.