Each element in a tree is a node. We need to define a node before we proceed to define a binary tree as a tree consists of nodes. We'll create a very simple node definition that has 3 properties, namely: left, right and data.
left − This holds the reference to the left child of this node.
right − This holds the reference to the right child of this node.
data − This holds the reference to the data we want to store in this node.
Let us see the code representation of such a structure.
Examle
class Node {
constructor(data, left = null, right = null) {
this.data = data;
this.left = left;
this.right = right;
}
}We've defined the Node data structure with a constructor that takes 3 properties, data left and right. We'll mostly just create a node with null left and right properties as we'll be inserting values at leaves.
For ease of use, we'll define Node as a property of the BinarySearchTree class that we'll create in order to keep this class within the place we use it.
Note that such nodes with 2 explicit left and right properties are needed for binary trees. For multiway trees like B trees or B+ trees, we define a property called children which is an array (or some other container like data structure).