Simple Hash Table implemented with separate chaining then open addressing collision strategy

hashtable-simple.js

function HashTable() {
  this._bucketSize = 23;
  this._buckets = [];
  this._buckets.length = this._bucketSize;
}

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

open-addressing.js

HashTable.prototype.put = function (key, value) {
  if (typeof(key) !== 'number' && typeof(key) !== 'string') {
    throw 'Invalid key type';
  }
  
  var hash = this.computeHash(key);
  if (this._buckets[hash] === undefined) {
    this._buckets[hash] = {};
    this._buckets[hash][key] = value;
    return;
  } else if (this._buckets[hash].hasOwnProperty(key)) {
    throw 'Duplicate not allowed';
  }
  
  var bucketId = hash + 1;
  
  do {
    if (bucketId >= this._bucketSize) {
      bucketId = 0;
    }
    
    if (this._buckets[bucketId] === undefined) {
      this._buckets[bucketId] = {};
      this._buckets[bucketId][key] = value;
      return;
    }
    
    bucketId++;
  } while (bucketId !== hash);

  throw 'HashTable is full, a rehash is needed';
};

HashTable.prototype.get = function (key) {
  if (typeof(key) !== 'number' && typeof(key) !== 'string') {
    return undefined;
  }
  
  var hash = this.computeHash(key);
  if (this._buckets[hash] === undefined) {
    return undefined;
  } else if (this._buckets[hash].hasOwnProperty(key)) {
    return this._buckets[hash][key];
  }
  
  var bucketId = hash + 1;
  
  do {
    if (bucketId >= this._bucketSize) {
      bucketId = 0;
    }
    
    if (this._buckets[bucketId] === undefined) {
      return undefined;
    } else if (this._buckets[bucketId].hasOwnProperty(key)) {
      return this._buckets[hash][key];
    }
    bucketId++;
  } while (bucketId != hash);
  return undefined;
};

separate-chaining.js

HashTable.prototype.put = function (key, value) {
  if (typeof(key) !== 'number' && typeof(key) !== 'string') {
    throw 'Invalid key type';
  }
  
  var hash = this.computeHash(key);
  if (this._buckets[hash] === undefined) {
    this._buckets[hash] = {};
  }
  
  var chain = this._buckets[hash];
  if (chain.hasOwnProperty(key)) {
    throw 'Duplicates not allowed';
  }
  chain[key] = value;
};

HashTable.prototype.get = function (key) {
  if (typeof(key) !== 'number' && typeof(key) !== 'string') {
    return undefined;
  }
  
  var hash = this.computeHash(key);
  if (this._buckets[hash] === undefined) {
    return undefined;
  }
  
  var chain = this._buckets[hash];
  if (chain.hasOwnProperty(key)) {
    return chain[key];
  }
  
  return undefined;
};