Dictionary implementation using Trie Tree

dict.js

// Classic Trie tree implementation for a dictionary that also supports wildcard search


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

class Dictionary {
  constructor(arr) {
    this.root = new TrieNode();
    arr.forEach((w) => this.insert(w));
  }

  insert(word) {
    let crawl = this.root;
    for (let j = 0; j < word.length; j++) {
      const ch = word.charAt(j);
      if (!crawl.children[ch]) { // if node does not exists for current character
        crawl.children[ch] = new TrieNode(j === word.length - 1);
      }
      crawl = crawl.children[ch]; // move to next node for the character
    }
  }

  isInDictRecur(word, node, index) {
    if (!node) return false;
    if (index === word.length && node.isEndOfWord) return true;
    const ch = word.charAt(index);
    if (ch === '*') {
      if (index === word.length - 1) return true; // when '*' is last
      return Object.keys(node.children).some((keyChar) => {
        return this.isInDictRecur(word, node.children[keyChar], index + 1);
      });
    } else {
      return this.isInDictRecur(word, node.children[ch], index + 1);
    }
  }

  isInDict(word) {
    return this.isInDictRecur(word, this.root, 0);
  }
}

const wordArray = ['cat', 'car', 'boo', 'bar'];
const dict = new Dictionary(wordArray);
console.log(dict.isInDict('cat')); // true
console.log(dict.isInDict('*a*')); // true
console.log(dict.isInDict('cr*')); // false
console.log(dict.isInDict('wat')); // false
console.log(dict.isInDict('boo')); // true
console.log(dict.isInDict('b*o')); // true