var associativeArray = {};
associativeArray["one"] = "First";
associativeArray["two"] = "Second";
associativeArray["three"] = "Third";

如果你来自面向对象的语言，你应该看看这篇文章。

所有现代浏览器都支持JavaScript Map对象。有几个原因使得使用Map比使用Object更好:

Object有一个原型，所以映射中有默认键。 对象的键是字符串，它们可以是Map的任何值。 当你必须跟踪对象的大小时，你可以很容易地获得Map的大小。

例子:

var myMap = new Map();

var keyObj = {},
    keyFunc = function () {},
    keyString = "a string";

myMap.set(keyString, "value associated with 'a string'");
myMap.set(keyObj, "value associated with keyObj");
myMap.set(keyFunc, "value associated with keyFunc");

myMap.size; // 3

myMap.get(keyString);    // "value associated with 'a string'"
myMap.get(keyObj);       // "value associated with keyObj"
myMap.get(keyFunc);      // "value associated with keyFunc"

如果希望垃圾收集没有从其他对象引用的键，可以考虑使用WeakMap而不是Map。

在c#中，代码如下:

Dictionary<string,int> dictionary = new Dictionary<string,int>();
dictionary.add("sample1", 1);
dictionary.add("sample2", 2);

or

var dictionary = new Dictionary<string, int> {
    {"sample1", 1},
    {"sample2", 2}
};

在JavaScript中:

var dictionary = {
    "sample1": 1,
    "sample2": 2
}

c#字典对象包含有用的方法，如dictionary. containskey ()

在JavaScript中，我们可以像这样使用hasOwnProperty:

if (dictionary.hasOwnProperty("sample1"))
    console.log("sample1 key found and its value is"+ dictionary["sample1"]);

https://gist.github.com/alexhawkins/f6329420f40e5cafa0a4

var HashTable = function() {
  this._storage = [];
  this._count = 0;
  this._limit = 8;
}


HashTable.prototype.insert = function(key, value) {

  // Create an index for our storage location by passing
  // it through our hashing function
  var index = this.hashFunc(key, this._limit);

  // Retrieve the bucket at this particular index in
  // our storage, if one exists
  //[[ [k,v], [k,v], [k,v] ] , [ [k,v], [k,v] ]  [ [k,v] ] ]
  var bucket = this._storage[index]

  // Does a bucket exist or do we get undefined
  // when trying to retrieve said index?
  if (!bucket) {
    // Create the bucket
    var bucket = [];
    // Insert the bucket into our hashTable
    this._storage[index] = bucket;
  }

  var override = false;

  // Now iterate through our bucket to see if there are any conflicting
  // key value pairs within our bucket. If there are any, override them.
  for (var i = 0; i < bucket.length; i++) {
    var tuple = bucket[i];
    if (tuple[0] === key) {

      // Override value stored at this key
      tuple[1] = value;
      override = true;
    }
  }

  if (!override) {
    // Create a new tuple in our bucket.
    // Note that this could either be the new empty bucket we created above
    // or a bucket with other tupules with keys that are different than
    // the key of the tuple we are inserting. These tupules are in the same
    // bucket because their keys all equate to the same numeric index when
    // passing through our hash function.
    bucket.push([key, value]);
    this._count++

    // Now that we've added our new key/val pair to our storage
    // let's check to see if we need to resize our storage
    if (this._count > this._limit * 0.75) {
      this.resize(this._limit * 2);
    }
  }
  return this;
};


HashTable.prototype.remove = function(key) {
  var index = this.hashFunc(key, this._limit);
  var bucket = this._storage[index];
  if (!bucket) {
    return null;
  }

  // Iterate over the bucket
  for (var i = 0; i < bucket.length; i++) {
    var tuple = bucket[i];

    // Check to see if key is inside bucket
    if (tuple[0] === key) {

      // If it is, get rid of this tuple
      bucket.splice(i, 1);
      this._count--;
      if (this._count < this._limit * 0.25) {
        this._resize(this._limit / 2);
      }
      return tuple[1];
    }
  }
};


HashTable.prototype.retrieve = function(key) {
  var index = this.hashFunc(key, this._limit);
  var bucket = this._storage[index];

  if (!bucket) {
    return null;
  }

  for (var i = 0; i < bucket.length; i++) {
    var tuple = bucket[i];
    if (tuple[0] === key) {
      return tuple[1];
    }
  }

  return null;
};


HashTable.prototype.hashFunc = function(str, max) {
  var hash = 0;
  for (var i = 0; i < str.length; i++) {
    var letter = str[i];
    hash = (hash << 5) + letter.charCodeAt(0);
    hash = (hash & hash) % max;
  }
  return hash;
};


HashTable.prototype.resize = function(newLimit) {
  var oldStorage = this._storage;

  this._limit = newLimit;
  this._count = 0;
  this._storage = [];

  oldStorage.forEach(function(bucket) {
    if (!bucket) {
      return;
    }
    for (var i = 0; i < bucket.length; i++) {
      var tuple = bucket[i];
      this.insert(tuple[0], tuple[1]);
    }
  }.bind(this));
};


HashTable.prototype.retrieveAll = function() {
  console.log(this._storage);
  //console.log(this._limit);
};

/******************************TESTS*******************************/

var hashT = new HashTable();

hashT.insert('Alex Hawkins', '510-599-1930');
//hashT.retrieve();
//[ , , , [ [ 'Alex Hawkins', '510-599-1930' ] ] ]
hashT.insert('Boo Radley', '520-589-1970');
//hashT.retrieve();
//[ , [ [ 'Boo Radley', '520-589-1970' ] ], , [ [ 'Alex Hawkins', '510-599-1930' ] ] ]
hashT.insert('Vance Carter', '120-589-1970').insert('Rick Mires', '520-589-1970').insert('Tom Bradey', '520-589-1970').insert('Biff Tanin', '520-589-1970');
//hashT.retrieveAll();
/*
[ ,
  [ [ 'Boo Radley', '520-589-1970' ],
    [ 'Tom Bradey', '520-589-1970' ] ],
  ,
  [ [ 'Alex Hawkins', '510-599-1930' ],
    [ 'Rick Mires', '520-589-1970' ] ],
  ,
  ,
  [ [ 'Biff Tanin', '520-589-1970' ] ] ]
*/

// Override example (Phone Number Change)
//
hashT.insert('Rick Mires', '650-589-1970').insert('Tom Bradey', '818-589-1970').insert('Biff Tanin', '987-589-1970');
//hashT.retrieveAll();

/*
[ ,
  [ [ 'Boo Radley', '520-589-1970' ],
    [ 'Tom Bradey', '818-589-1970' ] ],
  ,
  [ [ 'Alex Hawkins', '510-599-1930' ],
    [ 'Rick Mires', '650-589-1970' ] ],
  ,
  ,
  [ [ 'Biff Tanin', '987-589-1970' ] ] ]

*/

hashT.remove('Rick Mires');
hashT.remove('Tom Bradey');
//hashT.retrieveAll();

/*
[ ,
  [ [ 'Boo Radley', '520-589-1970' ] ],
  ,
  [ [ 'Alex Hawkins', '510-599-1930' ] ],
  ,
  ,
  [ [ 'Biff Tanin', '987-589-1970' ] ] ]


*/

hashT.insert('Dick Mires', '650-589-1970').insert('Lam James', '818-589-1970').insert('Ricky Ticky Tavi', '987-589-1970');
hashT.retrieveAll();


/* NOTICE HOW THE HASH TABLE HAS NOW DOUBLED IN SIZE UPON REACHING 75% CAPACITY, i.e. 6/8. It is now size 16.
 [,
  ,
  [ [ 'Vance Carter', '120-589-1970' ] ],
  [ [ 'Alex Hawkins', '510-599-1930' ],
    [ 'Dick Mires', '650-589-1970' ],
    [ 'Lam James', '818-589-1970' ] ],
  ,
  ,
  ,
  ,
  ,
  [ [ 'Boo Radley', '520-589-1970' ],
    [ 'Ricky Ticky Tavi', '987-589-1970' ] ],
  ,
  ,
  ,
  ,
  [ [ 'Biff Tanin', '987-589-1970' ] ] ]

*/

console.log(hashT.retrieve('Lam James'));  // 818-589-1970
console.log(hashT.retrieve('Dick Mires')); // 650-589-1970
console.log(hashT.retrieve('Ricky Ticky Tavi')); //987-589-1970
console.log(hashT.retrieve('Alex Hawkins')); // 510-599-1930
console.log(hashT.retrieve('Lebron James')); // null

var associativeArray = {};
associativeArray["one"] = "First";
associativeArray["two"] = "Second";
associativeArray["three"] = "Third";

如果你来自面向对象的语言，你应该看看这篇文章。

如果你需要你的键是任何对象，而不仅仅是字符串，那么你可以使用我的jshashtable。