Hash Table Data Structure created by aelshamy - https://repl.it/ExRG/2

Hash Table Data Structure.js

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

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

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

HashTable.prototype.insert = function (key, value){
    var index = this.hash(key);
    if(!this.buckets[index]) this.buckets[index] = new HashNode(key, value);
    else if(this.buckets[index].key === key) {
        this.buckets[index].value = value;
        
    }
    else{
        var currentNode = this.buckets[index];
        while(currentNode.next){
            if(currentNode.next.key === key){
                currentNode.next.value = value;
                return;
            }
            currentNode = currentNode.next;
        }
        currentNode.next = new HashNode(key, value);
    }
}


HashTable.prototype.get = function (key){
    var index = this.hash(key);
    if(!this.buckets[index]) return null;
    else{
        var currentNode = this.buckets[index];
        while(currentNode){
            if(currentNode.key === key) return currentNode.value;
            currentNode = currentNode.next;
        }
        return null;
    }
    
}

HashTable.prototype.retreiveAll = function (){
    var allNodes = [];
    
    for(var i= 0; i<this.numBuckets; i++){
        var currentNode = this.buckets[i];
        while(currentNode){
            allNodes.push(currentNode);
            currentNode  = currentNode.next;
        }
    }
    return allNodes;
    
}


var myHT = new HashTable(30);

myHT.insert('Dean', 'dean@gmail.com');
myHT.insert('Megan', 'megan@gmail.com');
myHT.insert('Dane', 'dane@gmail.com');
myHT.insert('Daen', 'dane@gmail.com');
myHT.insert('Amr', 'amr@gmail.com');


console.log(myHT.get('Megan'));
console.log(myHT.retreiveAll());