Java Program to Implement Binary Tree Data Structure

In this example, we will learn to implement the binary tree data structure in Java.

To understand this example, you should have the knowledge of the following Java programming topics:

Example: Java Program to Implement Binary Tree

// class to create nodes
class Node {
  int key;
  Node left, right;

  public Node(int item) {
  key = item;
  left = right = null;
  }
}

class BinaryTree {
  Node root;

  // Traverse tree
  public void traverseTree(Node node) {
    if (node != null) {
      traverseTree(node.left);
      System.out.print(" " + node.key);
      traverseTree(node.right);
    }
  }

  public static void main(String[] args) {

    // create an object of BinaryTree
    BinaryTree tree = new BinaryTree();

    // create nodes of the tree
    tree.root = new Node(1);
    tree.root.left = new Node(2);
    tree.root.right = new Node(3);
    tree.root.left.left = new Node(4);

    System.out.print("\nBinary Tree: ");
    tree.traverseTree(tree.root);
  }
}

Output