Javascript Binary Tree Impl.

gistfile1.js

var binaryTree = function(rootObj) {
      var that = {};
      
      that.key = rootObj;
      that.leftChild = undefined;
      that.rightChild = undefined;

      that.insertLeft = function(newNode) {
          if (this.leftChild === undefined) {
              this.leftChild = binaryTree(newNode);
          } else {
              var tree = binaryTree(newNode);
              tree.leftChild = this.leftChild;
              this.leftChild = tree;
          }
      };
      
      that.insertRight = function(newNode) {
          if (this.rightChild === undefined) {
              this.rightChild = binaryTree(newNode);
          } else {
              var tree = binaryTree(newNode);
              tree.rightChild = this.rightChild;
              this.rightChild = tree;
          }
      }
      
      return that;
};

var treeA = binaryTree("A");
treeA.insertLeft("B");
treeA.leftChild.insertRight("D");
treeA.insertRight("C");
treeA.rightChild.insertLeft("E");
treeA.rightChild.insertRight("F");

console.log(treeA.key);
console.log(treeA.leftChild.key);
console.log(treeA.rightChild.key);
console.log(treeA.leftChild.rightChild.key);
console.log(treeA.rightChild.leftChild.key);
console.log(treeA.rightChild.rightChild.key);