Trie Node Design and Initialization in DSA Javascript - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize a TrieNode with an empty children object.

DSA Javascript

class TrieNode {
  constructor() {
    this.children = [1];
    this.isEndOfWord = false;
  }
}

Drag options to blanks, or click blank then click option'

Anull

B[]

C{}

D''

Attempts:

3 left

💡 Hint

Common Mistakes

Using an array [] instead of an object for children.

Setting children to null or empty string.

The children property should be an empty object {} to store child nodes by character keys.

2fill in blank

medium

Complete the code to mark the node as the end of a word.

DSA Javascript

class TrieNode {
  constructor() {
    this.children = {};
    this.isEndOfWord = [1];
  }
}

Drag options to blanks, or click blank then click option'

Anull

Bfalse

Ctrue

Dundefined

Attempts:

3 left

💡 Hint

Common Mistakes

Setting isEndOfWord to true by default.

Using null or undefined instead of a boolean.

When initializing, isEndOfWord should be false because the node does not represent the end of a word yet.

3fill in blank

hard

Fix the error in the constructor to properly initialize children as an empty object.

DSA Javascript

class TrieNode {
  constructor() {
    this.children = new [1]();
    this.isEndOfWord = false;
  }
}

Drag options to blanks, or click blank then click option'

AArray

BSet

CMap

DObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using Array or Set which are not suitable for key-value pairs.

Using Map which requires different syntax.

Using new Object() correctly initializes an empty object for children.

4fill in blank

hard

Fill both blanks to complete the method that adds a child node for a character.

DSA Javascript

addChild(char) {
  if (!this.children.hasOwnProperty([1])) {
    this.children[[2]] = new TrieNode();
  }
}

Drag options to blanks, or click blank then click option'

A'char'

Bchar

C"char"

Dthis.char

Attempts:

3 left

💡 Hint

Common Mistakes

Using string literals like 'char' or "char" instead of the variable.

Using this.char which is undefined.

The character variable char is used as the key to check and add a child node.

5fill in blank

hard

Fill all three blanks to complete the method that checks if a child node exists for a character.

DSA Javascript

hasChild([1]) {
  return this.children.hasOwnProperty([2]) && this.children[[3]] !== undefined;
}

Drag options to blanks, or click blank then click option'

Achar

B'char'

Cchar.toLowerCase()

Dthis.char

Attempts:

3 left

💡 Hint

Common Mistakes

Using string literals instead of the variable.

Using this.char which is not defined.

The method uses the parameter char to check if the child exists in the children object.