Trie Node Design and Initialization in DSA Javascript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Trie node and what does it typically store?

A Trie node is a building block of a Trie data structure. It typically stores a collection of child nodes (usually in an object or array) representing possible next characters, and a boolean flag to mark if the node completes a valid word.

beginner

How do you initialize a Trie node in JavaScript?

You create an object with a children property (an empty object or Map) and an isEndOfWord boolean set to false. For example: <br><code>class TrieNode {<br>  constructor() {<br>    this.children = {};<br>    this.isEndOfWord = false;<br>  }<br>}</code>

intermediate

Why do we use an object or Map for children in a Trie node?

Because each child represents a possible next character, using an object or Map allows quick lookup of child nodes by character keys, making insertion and search efficient.

beginner

What does the isEndOfWord flag represent in a Trie node?

It marks whether the path from the root to this node forms a complete valid word stored in the Trie.

beginner

Show a simple JavaScript class for a Trie node with initialization.

<code>class TrieNode {<br>  constructor() {<br>    this.children = {};<br>    this.isEndOfWord = false;<br>  }<br>}</code>

What data structure is commonly used to store children in a Trie node?

A Object or Map

B Array of numbers

C Linked list

D Stack

Children are stored in an object or Map for quick character-based lookup.

What does the isEndOfWord boolean in a Trie node indicate?

A If the node has children

B If the node marks the end of a valid word

C If the node is the root

D If the node is empty

isEndOfWord marks if the path to this node forms a complete word.

How do you initialize the children property in a Trie node in JavaScript?

A As an empty string

B As a number zero

C As an empty object {}

D As null

Children are initialized as an empty object to hold child nodes.

Which of these is NOT a typical part of a Trie node?

A Parent pointer

B Children collection

C isEndOfWord flag

D Character value

Parent pointer is not usually stored in Trie nodes; children and end-of-word flag are standard.

What is the main purpose of a Trie node?

A To hold a stack of words

B To store numbers in sorted order

C To act as a queue

D To store a single character and link to next characters

Trie nodes store characters and link to possible next characters for word storage.

Explain how a Trie node is designed and initialized in JavaScript.

Think about what each node needs to store to represent words.

Describe the role of the isEndOfWord flag and children collection in a Trie node.

Consider how the Trie knows when a word finishes.