Binary Tree Node Structure in DSA Typescript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a binary tree node?

A binary tree node is a basic unit of a binary tree that contains data and references to at most two child nodes: left and right.

beginner

What are the main parts of a binary tree node?

A binary tree node has three main parts:

• Data: stores the value.
• Left child: reference to the left subtree.
• Right child: reference to the right subtree.

beginner

TypeScript code snippet: Define a simple binary tree node class.

class TreeNode {
  value: number;
  left: TreeNode | null;
  right: TreeNode | null;

  constructor(value: number) {
    this.value = value;
    this.left = null;
    this.right = null;
  }
}

beginner

Why do left and right child references sometimes hold null?

Because a node may not have a left or right child, so the reference is set to null to show the absence of a child node.

beginner

How does a binary tree node relate to real-life family trees?

Like a person in a family tree has parents and children, a binary tree node has a value and can have up to two children nodes, representing branches.

What does a binary tree node typically contain?

A Only data

B Only two child references

C Data and three child references

D Data and two child references

A binary tree node contains data and references to at most two children: left and right.

In TypeScript, what type should the left and right child references have in a binary tree node?

A number

B TreeNode | null

C string

D boolean

Left and right children can be either another TreeNode or null if no child exists.

If a node has no left child, what is the left reference set to?

A 0

B undefined

C null

D empty string

Null is used to indicate the absence of a child node.

How many children can a binary tree node have at most?

A Two

B One

C Three

D Unlimited

By definition, a binary tree node can have up to two children.

Which of these is NOT a part of a binary tree node?

A Parent reference

B Data value

C Left child reference

D Right child reference

A basic binary tree node does not usually store a parent reference.

Describe the structure of a binary tree node and its components.

Think about what each node holds and how it connects to others.

Explain why left and right child references can be null in a binary tree node.

Consider what happens when a node has no children.