hashtable-es6 created by mathrivest - https://repl.it/L7T7/8

hashtable-es6.js

class HashTable {
    constructor(size) {
        this.buckets = Array(size);
        this.numBuckets = this.buckets.length;
    }

    hash(key) {
        let total = 0;
        for (var i = 0; i < key.length; i++) {
            total += key.charCodeAt(i);
        }
        var bucket = total % this.numBuckets;
        return bucket;
    }

    insert(key, value) {
        let index = this.hash(key),
            newNode = new HashNode(key, value);
        if (!this.buckets[index]) {
            this.buckets[index] = newNode;
        } else if (this.buckets[index].key === key) {
            this.buckets[index].value = value;
        } else {
            let currentNode = this.buckets[index];
            while (currentNode.next) {
                if (currentNode.next.key === key) {
                    currentNode.next.value = value;
                    return;
                }
                currentNode = currentNode.next;
            }
            currentNode.next = newNode;
        }
    }
    
    get(key) {
        let index = this.hash(key);
        if(!this.buckets[index]) {
            return null;
        } else {
            let currentNode = this.buckets[index];
            while(currentNode) {
                if(currentNode.key === key) {
                    return currentNode.value;
                }
                currentNode = currentNode.next;
            }
            return null;
        }
    }
    
    retrieveAll() {
        let allNodes = [];
        for (var i = 0; i< this.numBuckets; i++) {
            let currentNode = this.buckets[i];
            
            while(currentNode) {
                allNodes.push(currentNode);
                currentNode = currentNode.next;
            }
        }
        return allNodes;
    }
}

function HashNode(key, value, next) {
    this.key = key;
    this.value = value;
    this.next = next || null;
}

const myHT = new HashTable(30);

myHT.insert('Steve', 'steve@allo.com');
myHT.insert('Paul', 'paul@allo.com');
myHT.insert('Jerry', 'jerry.allo@allo.com');
myHT.insert('Dane', 'dane@allo.com');
myHT.insert('Dean', 'dean@allo.com');
myHT.insert('Jerry', 'jerry@gmail.com');
myHT.insert('Dane', 'dane@gmail.com');
myHT.insert('Dean', 'dean@gmail.com');

console.log(myHT);

console.log(myHT.retrieveAll());