trie.js

/** Node in Trie **/
function Node() {  
    this.keys = new Map();  
    this.end = false;  
    this.setEnd = function () {    
        this.end = true;  
    };  
    this.isEnd = function () {    
        return this.end;  
    }
}

function Trie() {  
        this.root = new Node();  
        this.add = function (input, node = this.root) {    
            if (input.length === 0) {     
                node.setEnd();      
                return;    
            } else if (!node.keys.has(input[0])) {      
                node.keys.set(input[0], new Node());      
                return this.add(input.substr(1), node.keys.get(input[0]));    
            } else {      
                return this.add(input.substr(1), node.keys.get(input[0]));    
            }  
        }  
        this.isWord = function (word) {    
            let node = this.root;    
            while (word.length > 1) {      
                if (!node.keys.has(word[0])) {        
                    return false;      
                } else {        
                    node = node.keys.get(word[0]);       
                    word = word.substr(1);      
                }    
            }    
            return (node.keys.has(word) && node.keys.get(word).isEnd()) ? true : false;  
        }  
            this.print = function () {    
                let words = new Array();    
                let search = function (node = this.root, string) {      
                    if (node.keys.size != 0) {        
                        for (let letter of node.keys.keys()) {          
                            search(node.keys.get(letter), string.concat(letter));        
                        }        
                        if (node.isEnd()) {          
                            words.push(string);        
                        }      
                    } else {        
                        string.length > 0 ? words.push(string) : undefined;        
                        return;      
                    }    
                };    
                search(this.root, new String());    
                return words.length > 0 ? words : null;  
    }
}