You can use the same algorithm to count a number of Leaf Nodes in the Binary Tree which we have used in the last article, while printing all leaf nodes of a binary tree in Java, using both recursion and iteration. The logic is same for leaf node, any node whose left and right children is null is known as leaf node in binary tree. They are the nodes which resides in the last level of binary tree and they don't have any children. In order to count total number of leaf nodes in binary tree, you need to traverse the tree and increase the count variable whenever you see a leaf node. Since binary tree is an essential data structure and algorithm topics for programming interviews, its better to prepare these kind of questions. I'll show how to solve this using both recursion and iteration in Java in this article.