本文探讨了JavaScript中哈希映射的有效实现，对比了不同方法的优劣，并提供了具体的代码示例，包括基于字符串键的哈希映射和解决对象键冲突的策略。
本文翻译自：JavaScript Hashmap Equivalent
As made clear in update 3 on this answer , this notation: 正如在这个答案的更新3中所表明的那样，这种表示法：
var hash = {};
hash[X]
does not actually hash the object X ; 实际上并没有散列对象X ; it actually just converts X to a string (via .toString() if it's an object, or some other built-in conversions for various primitive types) and then looks that string up, without hashing it, in " hash ". 它实际上只是将X转换为字符串（如果它是一个对象，则通过.toString() ，或者为各种基本类型转换为其他一些内置转换），然后在“ hash ”中查找该字符串，而不对其进行hash 。 Object equality is also not checked - if two different objects have the same string conversion, they will just overwrite each other. 也不检查对象相等性 - 如果两个不同的对象具有相同的字符串转换，它们将仅相互覆盖。
Given this - are there any efficient implementations of hashmaps in javascript? 鉴于此 - 在JavaScript中是否有任何有效的哈希映射实现？ (For example, the 2nd Google result of javascript hashmap yields an implementation which is O(n) for any operation. Various other results ignore the fact that different objects with equivalent string representations overwrite each other. （例如， javascript hashmap的第二个Google结果产生了任何操作的O（n）实现。各种其他结果忽略了具有等效字符串表示的不同对象相互覆盖的事实。
#1楼
参考：https://stackoom.com/question/1Xo0/JavaScript-Hashmap等效
#2楼
I've implemented a JavaScript HashMap which code can be obtained from http://github.com/lambder/HashMapJS/tree/master 我已经实现了一个JavaScript HashMap，可以从http://github.com/lambder/HashMapJS/tree/master获取代码
Here is the code: 这是代码：
/*
=====================================================================
@license MIT
@author Lambder
@copyright 2009 Lambder.
@end
=====================================================================
*/
var HashMap = function() {
this.initialize();
}
HashMap.prototype = {
hashkey_prefix: "<#HashMapHashkeyPerfix>",
hashcode_field: "<#HashMapHashkeyPerfix>",
initialize: function() {
this.backing_hash = {};
this.code = 0;
},
/*
maps value to key returning previous assocciation
*/
put: function(key, value) {
var prev;
if (key && value) {
var hashCode = key[this.hashcode_field];
if (hashCode) {
prev = this.backing_hash[hashCode];
} else {
this.code += 1;
hashCode = this.hashkey_prefix + this.code;
key[this.hashcode_field] = hashCode;
}
this.backing_hash[hashCode] = value;
}
return prev;
},
/*
returns value associated with given key
*/
get: function(key) {
var value;
if (key) {
var hashCode = key[this.hashcode_field];
if (hashCode) {
value = this.backing_hash[hashCode];
}
}
return value;
},
/*
deletes association by given key.
Returns true if the assocciation existed, false otherwise
*/
del: function(key) {
var success = false;
if (key) {
var hashCode = key[this.hashcode_field];
if (hashCode) {
var prev = this.backing_hash[hashCode];
this.backing_hash[hashCode] = undefined;
if(prev !== undefined)
success = true;
}
}
return success;
}
}
//// Usage
// creation
var my_map = new HashMap();
// insertion
var a_key = {};
var a_value = {struct: "structA"};
var b_key = {};
var b_value = {struct: "structB"};
var c_key = {};
var c_value = {struct: "structC"};
my_map.put(a_key, a_value);
my_map.put(b_key, b_value);
var prev_b = my_map.put(b_key, c_value);
// retrieval
if(my_map.get(a_key) !== a_value){
throw("fail1")
}
if(my_map.get(b_key) !== c_value){
throw("fail2")
}
if(prev_b !== b_value){
throw("fail3")
}
// deletion
var a_existed = my_map.del(a_key);
var c_existed = my_map.del(c_key);
var a2_existed = my_map.del(a_key);
if(a_existed !== true){
throw("fail4")
}
if(c_existed !== false){
throw("fail5")
}
if(a2_existed !== false){
throw("fail6")
}
#3楼
My Map Implementation, derived from Christoph's example: 我的地图实现，源自Christoph的例子：
Example Usage: 用法示例：
var map = new Map(); //creates an "in-memory" map
var map = new Map("storageId"); //creates a map that is loaded/persisted using html5 storage
function Map(storageId) {
this.current = undefined;
this.size = 0;
this.storageId = storageId;
if (this.storageId) {
this.keys = new Array();
this.disableLinking();
}
}
Map.noop = function() {
return this;
};
Map.illegal = function() {
throw new Error("illegal operation for maps without linking");
};
// map initialisation from existing object
// doesn't add inherited properties if not explicitly instructed to:
// omitting foreignKeys means foreignKeys === undefined, i.e. == false
// --> inherited properties won't be added
Map.from = function(obj, foreignKeys) {
var map = new Map;
for(var prop in obj) {
if(foreignKeys || obj.hasOwnProperty(prop))
map.put(prop, obj[prop]);
}
return map;
};
Map.prototype.disableLinking = function() {
this.link = Map.noop;
this.unlink = Map.noop;
this.disableLinking = Map.noop;
this.next = Map.illegal;
this.key = Map.illegal;
this.value = Map.illegal;
// this.removeAll = Map.illegal;
return this;
};
// overwrite in Map instance if necessary
Map.prototype.hash = function(value) {
return (typeof value) + ' ' + (value instanceof Object ?
(value.__hash || (value.__hash = ++arguments.callee.current)) :
value.toString());
};
Map.prototype.hash.current = 0;
// --- mapping functions
Map.prototype.get = function(key) {
var item = this[this.hash(key)];
if (item === undefined) {
if (this.storageId) {
try {
var itemStr = localStorage.getItem(this.storageId + key);
if (itemStr && itemStr !== 'undefined') {
item = JSON.parse(itemStr);
this[this.hash(key)] = item;
this.keys.push(key);
++this.size;
}
} catch (e) {
console.log(e);
}
}
}
return item === undefined ? undefined : item.value;
};
Map.prototype.put = function(key, value) {
var hash = this.hash(key);
if(this[hash] === undefined) {
var item = { key : key, value : value };
this[hash] = item;
this.link(item);
++this.size;
}
else this[hash].value = value;
if (this.storageId) {
this.keys.push(key);
try {
localStorage.setItem(this.storageId + key, JSON.stringify(this[hash]));
} catch (e) {
console.log(e);
}
}
return this;
};
Map.prototype.remove = function(key) {
var hash = this.hash(key);
var item = this[hash];
if(item !== undefined) {
--this.size;
this.unlink(item);
delete this[hash];
}
if (this.storageId) {
try {
localStorage.setItem(this.storageId + key, undefined);
} catch (e) {
console.log(e);
}
}
return this;
};
// only works if linked
Map.prototype.removeAll = function() {
if (this.storageId) {
for (var i=0; i<this.keys.length; i++) {
this.remove(this.keys[i]);
}
this.keys.length = 0;
} else {
while(this.size)
this.remove(this.key());
}
return this;
};
// --- linked list helper functions
Map.prototype.link = function(item) {
if (this.storageId) {
return;
}
if(this.size == 0) {
item.prev = item;
item.next = item;
this.current = item;
}
else {
item.prev = this.current.prev;
item.prev.next = item;
item.next = this.current;
this.current.prev = item;
}
};
Map.prototype.unlink = function(item) {
if (this.storageId) {
return;
}
if(this.size == 0)
this.current = undefined;
else {
item.prev.next = item.next;
item.next.prev = item.prev;
if(item === this.current)
this.current = item.next;
}
};
// --- iterator functions - only work if map is linked
Map.prototype.next = function() {
this.current = this.current.next;
};
Map.prototype.key = function() {
if (this.storageId) {
return undefined;
} else {
return this.current.key;
}
};
Map.prototype.value = function() {
if (this.storageId) {
return undefined;
}
return this.current.value;
};
#4楼
Here is an easy and convenient way of using something similar to the java map: 这是一种使用类似于java地图的简单方便的方法：
var map= {
'map_name_1': map_value_1,
'map_name_2': map_value_2,
'map_name_3': map_value_3,
'map_name_4': map_value_4
}
And to get the value: 并获得价值：
alert( map['map_name_1'] ); // fives the value of map_value_1
...... etc .....
#5楼
Adding yet another solution: HashMap is pretty much the first class I ported from Java to Javascript. 添加另一个解决方案： HashMap几乎是我从Java移植到Javascript的第一个类。 You could say there is a lot of overhead, but the implementation is almost 100% equal to Java's implementation and includes all interfaces and subclasses. 你可以说有很多开销，但实现几乎100％等于Java的实现，包括所有接口和子类。
The project can be found here: https://github.com/Airblader/jsava I'll also attach the (current) source code for the HashMap class, but as stated it also depends on the super class etc. The OOP framework used is qooxdoo. 该项目可以在这里找到： https ： //github.com/Airblader/jsava我还将附加HashMap类的（当前）源代码，但如上所述，它还依赖于超类等。使用的OOP框架是qooxdoo。
Edit: Please note that this code is already out-dated and refer to the github project for the current work. 编辑：请注意，此代码已过时，请参阅当前工作的github项目。 As of writing this, there is also an ArrayList implementation. 在撰写本文时，还有一个ArrayList实现。
qx.Class.define( 'jsava.util.HashMap', {
extend: jsava.util.AbstractMap,
implement: [jsava.util.Map, jsava.io.Serializable, jsava.lang.Cloneable],
construct: function () {
var args = Array.prototype.slice.call( arguments ),
initialCapacity = this.self( arguments ).DEFAULT_INITIAL_CAPACITY,
loadFactor = this.self( arguments ).DEFAULT_LOAD_FACTOR;
switch( args.length ) {
case 1:
if( qx.Class.implementsInterface( args[0], jsava.util.Map ) ) {
initialCapacity = Math.max( ((args[0].size() / this.self( arguments ).DEFAULT_LOAD_FACTOR) | 0) + 1,
this.self( arguments ).DEFAULT_INITIAL_CAPACITY );
loadFactor = this.self( arguments ).DEFAULT_LOAD_FACTOR;
} else {
initialCapacity = args[0];
}
break;
case 2:
initialCapacity = args[0];
loadFactor = args[1];
break;
}
if( initialCapacity < 0 ) {
throw new jsava.lang.IllegalArgumentException( 'Illegal initial capacity: ' + initialCapacity );
}
if( initialCapacity > this.self( arguments ).MAXIMUM_CAPACITY ) {
initialCapacity = this.self( arguments ).MAXIMUM_CAPACITY;
}
if( loadFactor <= 0 || isNaN( loadFactor ) ) {
throw new jsava.lang.IllegalArgumentException( 'Illegal load factor: ' + loadFactor );
}
var capacity = 1;
while( capacity < initialCapacity ) {
capacity <<= 1;
}
this._loadFactor = loadFactor;
this._threshold = (capacity * loadFactor) | 0;
this._table = jsava.JsavaUtils.emptyArrayOfGivenSize( capacity, null );
this._init();
},
statics: {
serialVersionUID: 1,
DEFAULT_INITIAL_CAPACITY: 16,
MAXIMUM_CAPACITY: 1 << 30,
DEFAULT_LOAD_FACTOR: 0.75,
_hash: function (hash) {
hash ^= (hash >>> 20) ^ (hash >>> 12);
return hash ^ (hash >>> 7) ^ (hash >>> 4);
},
_indexFor: function (hashCode, length) {
return hashCode & (length - 1);
},
Entry: qx.Class.define( 'jsava.util.HashMap.Entry', {
extend: jsava.lang.Object,
implement: [jsava.util.Map.Entry],
construct: function (hash, key, value, nextEntry) {
this._value = value;
this._next = nextEntry;
this._key = key;
this._hash = hash;
},
members: {
_key: null,
_value: null,
/** @type jsava.util.HashMap.Entry */
_next: null,
/** @type Number */
_hash: 0,
getKey: function () {
return this._key;
},
getValue: function () {
return this._value;
},
setValue: function (newValue) {
var oldValue = this._value;
this._value = newValue;
return oldValue;
},
equals: function (obj) {
if( obj === null || !qx.Class.implementsInterface( obj, jsava.util.HashMap.Entry ) ) {
return false;
}
/** @type jsava.util.HashMap.Entry */
var entry = obj,
key1 = this.getKey(),
key2 = entry.getKey();
if( key1 === key2 || (key1 !== null && key1.equals( key2 )) ) {
var value1 = this.getValue(),
value2 = entry.getValue();
if( value1 === value2 || (value1 !== null && value1.equals( value2 )) ) {
return true;
}
}
return false;
},
hashCode: function () {
return (this._key === null ? 0 : this._key.hashCode()) ^
(this._value === null ? 0 : this._value.hashCode());
},
toString: function () {
return this.getKey() + '=' + this.getValue();
},
/**
* This method is invoked whenever the value in an entry is
* overwritten by an invocation of put(k,v) for a key k that's already
* in the HashMap.
*/
_recordAccess: function (map) {
},
/**
* This method is invoked whenever the entry is
* removed from the table.
*/
_recordRemoval: function (map) {
}
}
} )
},
members: {
/** @type jsava.util.HashMap.Entry[] */
_table: null,
/** @type Number */
_size: 0,
/** @type Number */
_threshold: 0,
/** @type Number */
_loadFactor: 0,
/** @type Number */
_modCount: 0,
/** @implements jsava.util.Set */
__entrySet: null,
/**
* Initialization hook for subclasses. This method is called
* in all constructors and pseudo-constructors (clone, readObject)
* after HashMap has been initialized but before any entries have
* been inserted. (In the absence of this method, readObject would
* require explicit knowledge of subclasses.)
*/
_init: function () {
},
size: function () {
return this._size;
},
isEmpty: function () {
return this._size === 0;
},
get: function (key) {
if( key === null ) {
return this.__getForNullKey();
}
var hash = this.self( arguments )._hash( key.hashCode() );
for( var entry = this._table[this.self( arguments )._indexFor( hash, this._table.length )];
entry !== null; entry = entry._next ) {
/** @type jsava.lang.Object */
var k;
if( entry._hash === hash && ((k = entry._key) === key || key.equals( k )) ) {
return entry._value;
}
}
return null;
},
__getForNullKey: function () {
for( var entry = this._table[0]; entry !== null; entry = entry._next ) {
if( entry._key === null ) {
return entry._value;
}
}
return null;
},
containsKey: function (key) {
return this._getEntry( key ) !== null;
},
_getEntry: function (key) {
var hash = (key === null) ? 0 : this.self( arguments )._hash( key.hashCode() );
for( var entry = this._table[this.self( arguments )._indexFor( hash, this._table.length )];
entry !== null; entry = entry._next ) {
/** @type jsava.lang.Object */
var k;
if( entry._hash === hash
&& ( ( k = entry._key ) === key || ( key !== null && key.equals( k ) ) ) ) {
return entry;
}
}
return null;
},
put: function (key, value) {
if( key === null ) {
return this.__putForNullKey( value );
}
var hash = this.self( arguments )._hash( key.hashCode() ),
i = this.self( arguments )._indexFor( hash, this._table.length );
for( var entry = this._table[i]; entry !== null; entry = entry._next ) {
/** @type jsava.lang.Object */
var k;
if( entry._hash === hash && ( (k = entry._key) === key || key.equals( k ) ) ) {
var oldValue = entry._value;
entry._value = value;
entry._recordAccess( this );
return oldValue;
}
}
this._modCount++;
this._addEntry( hash, key, value, i );
return null;
},
__putForNullKey: function (value) {
for( var entry = this._table[0]; entry !== null; entry = entry._next ) {
if( entry._key === null ) {
var oldValue = entry._value;
entry._value = value;
entry._recordAccess( this );
return oldValue;
}
}
this._modCount++;
this._addEntry( 0, null, value, 0 );
return null;
},
__putForCreate: function (key, value) {
var hash = (key === null) ? 0 : this.self( arguments )._hash( key.hashCode() ),
i = this.self( arguments )._indexFor( hash, this._table.length );
for( var entry = this._table[i]; entry !== null; entry = entry._next ) {
/** @type jsava.lang.Object */
var k;
if( entry._hash === hash
&& ( (k = entry._key) === key || ( key !== null && key.equals( k ) ) ) ) {
entry._value = value;
return;
}
}
this._createEntry( hash, key, value, i );
},
__putAllForCreate: function (map) {
var iterator = map.entrySet().iterator();
while( iterator.hasNext() ) {
var entry = iterator.next();
this.__putForCreate( entry.getKey(), entry.getValue() );
}
},
_resize: function (newCapacity) {
var oldTable = this._table,
oldCapacity = oldTable.length;
if( oldCapacity === this.self( arguments ).MAXIMUM_CAPACITY ) {
this._threshold = Number.MAX_VALUE;
return;
}
var newTable = jsava.JsavaUtils.emptyArrayOfGivenSize( newCapacity, null );
this._transfer( newTable );
this._table = newTable;
this._threshold = (newCapacity * this._loadFactor) | 0;
},
_transfer: function (newTable) {
var src = this._table,
newCapacity = newTable.length;
for( var j = 0; j < src.length; j++ ) {
var entry = src[j];
if( entry !== null ) {
src[j] = null;
do {
var next = entry._next,
i = this.self( arguments )._indexFor( entry._hash, newCapacity );
entry._next = newTable[i];
newTable[i] = entry;
entry = next;
} while( entry !== null );
}
}
},
putAll: function (map) {
var numKeyToBeAdded = map.size();
if( numKeyToBeAdded === 0 ) {
return;
}
if( numKeyToBeAdded > this._threshold ) {
var targetCapacity = (numKeyToBeAdded / this._loadFactor + 1) | 0;
if( targetCapacity > this.self( arguments ).MAXIMUM_CAPACITY ) {
targetCapacity = this.self( arguments ).MAXIMUM_CAPACITY;
}
var newCapacity = this._table.length;
while( newCapacity < targetCapacity ) {
newCapacity <<= 1;
}
if( newCapacity > this._table.length ) {
this._resize( newCapacity );
}
}
var iterator = map.entrySet().iterator();
while( iterator.hasNext() ) {
var entry = iterator.next();
this.put( entry.getKey(), entry.getValue() );
}
},
remove: function (key) {
var entry = this._removeEntryForKey( key );
return entry === null ? null : entry._value;
},
_removeEntryForKey: function (key) {
var hash = (key === null) ? 0 : this.self( arguments )._hash( key.hashCode() ),
i = this.self( arguments )._indexFor( hash, this._table.length ),
prev = this._table[i],
entry = prev;
while( entry !== null ) {
var next = entry._next,
/** @type jsava.lang.Object */
k;
if( entry._hash === hash
&& ( (k = entry._key) === key || ( key !== null && key.equals( k ) ) ) ) {
this._modCount++;
this._size--;
if( prev === entry ) {
this._table[i] = next;
} else {
prev._next = next;
}
entry._recordRemoval( this );
return entry;
}
prev = entry;
entry = next;
}
return entry;
},
_removeMapping: function (obj) {
if( obj === null || !qx.Class.implementsInterface( obj, jsava.util.Map.Entry ) ) {
return null;
}
/** @implements jsava.util.Map.Entry */
var entry = obj,
key = entry.getKey(),
hash = (key === null) ? 0 : this.self( arguments )._hash( key.hashCode() ),
i = this.self( arguments )._indexFor( hash, this._table.length ),
prev = this._table[i],
e = prev;
while( e !== null ) {
var next = e._next;
if( e._hash === hash && e.equals( entry ) ) {
this._modCount++;
this._size--;
if( prev === e ) {
this._table[i] = next;
} else {
prev._next = next;
}
e._recordRemoval( this );
return e;
}
prev = e;
e = next;
}
return e;
},
clear: function () {
this._modCount++;
var table = this._table;
for( var i = 0; i < table.length; i++ ) {
table[i] = null;
}
this._size = 0;
},
containsValue: function (value) {
if( value === null ) {
return this.__containsNullValue();
}
var table = this._table;
for( var i = 0; i < table.length; i++ ) {
for( var entry = table[i]; entry !== null; entry = entry._next ) {
if( value.equals( entry._value ) ) {
return true;
}
}
}
return false;
},
__containsNullValue: function () {
var table = this._table;
for( var i = 0; i < table.length; i++ ) {
for( var entry = table[i]; entry !== null; entry = entry._next ) {
if( entry._value === null ) {
return true;
}
}
}
return false;
},
clone: function () {
/** @type jsava.util.HashMap */
var result = null;
try {
result = this.base( arguments );
} catch( e ) {
if( !qx.Class.isSubClassOf( e.constructor, jsava.lang.CloneNotSupportedException ) ) {
throw e;
}
}
result._table = jsava.JsavaUtils.emptyArrayOfGivenSize( this._table.length, null );
result.__entrySet = null;
result._modCount = 0;
result._size = 0;
result._init();
result.__putAllForCreate( this );
return result;
},
_addEntry: function (hash, key, value, bucketIndex) {
var entry = this._table[bucketIndex];
this._table[bucketIndex] = new (this.self( arguments ).Entry)( hash, key, value, entry );
if( this._size++ >= this._threshold ) {
this._resize( 2 * this._table.length );
}
},
_createEntry: function (hash, key, value, bucketIndex) {
var entry = this._table[bucketIndex];
this._table[bucketIndex] = new (this.self( arguments ).Entry)( hash, key, value, entry );
this._size++;
},
keySet: function () {
var keySet = this._keySet;
return keySet !== null ? keySet : ( this._keySet = new this.KeySet( this ) );
},
values: function () {
var values = this._values;
return values !== null ? values : ( this._values = new this.Values( this ) );
},
entrySet: function () {
return this.__entrySet0();
},
__entrySet0: function () {
var entrySet = this.__entrySet;
return entrySet !== null ? entrySet : ( this.__entrySet = new this.EntrySet( this ) );
},
/** @private */
HashIterator: qx.Class.define( 'jsava.util.HashMap.HashIterator', {
extend: jsava.lang.Object,
implement: [jsava.util.Iterator],
type: 'abstract',
/** @protected */
construct: function (thisHashMap) {
this.__thisHashMap = thisHashMap;
this._expectedModCount = this.__thisHashMap._modCount;
if( this.__thisHashMap._size > 0 ) {
var table = this.__thisHashMap._table;
while( this._index < table.length && ( this._next = table[this._index++] ) === null ) {
// do nothing
}
}
},
members: {
__thisHashMap: null,
/** @type jsava.util.HashMap.Entry */
_next: null,
/** @type Number */
_expectedModCount: 0,
/** @type Number */
_index: 0,
/** @type jsava.util.HashMap.Entry */
_current: null,
hasNext: function () {
return this._next !== null;
},
_nextEntry: function () {
if( this.__thisHashMap._modCount !== this._expectedModCount ) {
throw new jsava.lang.ConcurrentModificationException();
}
var entry = this._next;
if( entry === null ) {
throw new jsava.lang.NoSuchElementException();
}
if( (this._next = entry._next) === null ) {
var table = this.__thisHashMap._table;
while( this._index < table.length && ( this._next = table[this._index++] ) === null ) {
// do nothing
}
}
this._current = entry;
return entry;
},
remove: function () {
if( this._current === null ) {
throw new jsava.lang.IllegalStateException();
}
if( this.__thisHashMap._modCount !== this._expectedModCount ) {
throw new jsava.lang.ConcurrentModificationException();
}
var key = this._current._key;
this._current = null;
this.__thisHashMap._removeEntryForKey( key );
this._expectedModCount = this.__thisHashMap._modCount;
}
}
} ),
_newKeyIterator: function () {
return new this.KeyIterator( this );
},
_newValueIterator: function () {
return new this.ValueIterator( this );
},
_newEntryIterator: function () {
return new this.EntryIterator( this );
},
/** @private */
ValueIterator: qx.Class.define( 'jsava.util.HashMap.ValueIterator', {
extend: jsava.util.HashMap.HashIterator,
construct: function (thisHashMap) {
this.base( arguments, thisHashMap );
},
members: {
next: function () {
return this._nextEntry()._value;
}
}
} ),
/** @private */
KeyIterator: qx.Class.define( 'jsava.util.HashMap.KeyIterator', {
extend: jsava.util.HashMap.HashIterator,
construct: function (thisHashMap) {
this.base( arguments, thisHashMap );
},
members: {
next: function () {
return this._nextEntry().getKey();
}
}
} ),
/** @private */
EntryIterator: qx.Class.define( 'jsava.util.HashMap.EntryIterator', {
extend: jsava.util.HashMap.HashIterator,
construct: function (thisHashMap) {
this.base( arguments, thisHashMap );
},
members: {
next: function () {
return this._nextEntry();
}
}
} ),
/** @private */
KeySet: qx.Class.define( 'jsava.util.HashMap.KeySet', {
extend: jsava.util.AbstractSet,
construct: function (thisHashMap) {
this.base( arguments );
this.__thisHashMap = thisHashMap;
},
members: {
__thisHashMap: null,
iterator: function () {
return this.__thisHashMap._newKeyIterator();
},
size: function () {
return this.__thisHashMap._size;
},
contains: function (obj) {
return this.__thisHashMap.containsKey( obj );
},
remove: function (obj) {
return this.__thisHashMap._removeEntryForKey( obj ) !== null;
},
clear: function () {
this.__thisHashMap.clear();
}
}
} ),
/** @private */
Values: qx.Class.define( 'jsava.util.HashMap.Values', {
extend: jsava.util.AbstractCollection,
construct: function (thisHashMap) {
this.base( arguments );
this.__thisHashMap = thisHashMap;
},
members: {
__thisHashMap: null,
iterator: function () {
return this.__thisHashMap._newValueIterator();
},
size: function () {
return this.__thisHashMap._size;
},
contains: function (obj) {
return this.__thisHashMap.containsValue( obj );
},
clear: function () {
this.__thisHashMap.clear();
}
}
} ),
/** @private */
EntrySet: qx.Class.define( 'jsava.util.HashMap.EntrySet', {
extend: jsava.util.AbstractSet,
construct: function (thisHashMap) {
this.base( arguments );
this.__thisHashMap = thisHashMap;
},
members: {
__thisHashMap: null,
iterator: function () {
return this.__thisHashMap._newEntryIterator();
},
size: function () {
return this.__thisHashMap._size;
},
contains: function (obj) {
if( obj === null || !qx.Class.implementsInterface( obj, jsava.util.Map.Entry ) ) {
return false;
}
/** @implements jsava.util.Map.Entry */
var entry = obj,
candidate = this.__thisHashMap._getEntry( entry.getKey() );
return candidate !== null && candidate.equals( entry );
},
remove: function (obj) {
return this.__thisHashMap._removeMapping( obj ) !== null;
},
clear: function () {
this.__thisHashMap.clear();
}
}
} )
}
} );
#6楼
This looks like a pretty robust solution: https://github.com/flesler/hashmap . 这看起来像一个非常强大的解决方案： https ： //github.com/flesler/hashmap 。 It will even work well for functions and objects that look identical. 它甚至可以很好地用于看起来相同的功能和对象。 The only hack it uses is adding an obscure member to an object to identify it. 它唯一使用的是将一个不起眼的成员添加到一个对象来识别它。 If your program doesn't overwrite that obscure variable (its something like hashid ), you're golden. 如果你的程序没有覆盖那个模糊的变量（就像hashid那样 ），你就是金色的。
扫一扫
636
被折叠的 条评论
为什么被折叠?
到【灌水乐园】发言
