在javascript / jQuery中设置Java的数据结构

有没有办法在javascript中创建像java这样的Set数据结构（Unique Collections）？

Answer 1

对于一组字符串，我只使用值为true的对象。

var obj = {}; obj["foo"] = true; obj["bar"] = true; if(obj["foo"]) { // foo in set } 

这基本上是HashSet在Java中的工作方式，假设JavaScript对象是作为哈希表实现的（这是典型的）。

Answer 2

我编写了一个类似于Java的HashSet的哈希集的JavaScript实现。 它允许任何对象（不仅仅是字符串）用作集合成员。 它基于哈希表的键。

http://code.google.com/p/jshashtable/downloads/list

我保证会立即提供文档。 现在，源代码应该非常清楚地给你API，这是一个例子：

 var s = new HashSet(); var o1 = {name: "One"}, o2 = {name: "Two"}; s.add(o1); s.add(o2); s.add(o2); s.values(); // Array containing o1 and a single reference to o2 

Answer 3

好吧虽然它似乎是一个常见的问题，但我发现网上似乎是一个很好的Set类支持对象，我想要一个更简单的类，最后自己写一个…以防其他人发现它有用。 ..

 /** * A Javascript Class that represents a set of unique values * * Usage: * * var s = new jsSet(); * * s.add('a1'); s.add('a2'); * * s.list(); >> ['a1','a2'] * * s.remove('a1'); s.list(); >> ['a2'] * * s.contains('a1') >> false * * s.contains('a2') >> true * * can be chained * s.add(null).add('hello'); * * add array * s.addAll([ null, 'a', 'b' ]); * * remove array * s.addAll([ null, 'a', 'b' ]); * * retrieve the elements as a list * s.list(); * * size of the set * s.size(); * */ function jsSet() { // null can also be an element of the set, but needs // a separate indication to differentiate it from // the string "null" as well this.isNullAdded = false; // private member variable hence no 'this' var map = {}; // Scope for optimization // could be cached instead of generating each time // this.uniqueList = []; // returns true if the element is in this set, false otherwise this.contains = function(key) { if (key === null) return this.isNullAdded; else if (key === undefined) return false; else return map[key] ? true : false; }; // adds the element to the set this.add = function(val) { if (val === null) this.isNullAdded = true; else if (val !== undefined) map[val] = true; return this; }; // adds all the elements of the array to the set this.addAll = function(val) { if (val !== null && val !== undefined && val instanceof Array) { for ( var idx = 0; idx < val.length; idx++) { this.add(val[idx]); } } return this; }; // removes the specified element from the set this.remove = function(val) { if (val === null) this.isNullAdded = false; else if (val !== undefined) delete map[val]; return this; }; // removes all the element in the array from the set this.removeAll = function(val) { if (val !== null && val !== undefined && val instanceof Array) { for ( var idx = 0; idx < val.length; idx++) { console.log('val: %s:%s', idx, val[idx]); this.remove(val[idx]); } } return this; }; // empties the set of all values this.clear = function() { this.isNullAdded = false; map = {}; return this; }; // returns the number of elements in the set this.size = function() { return this.list().length; }; // returns true if the set is empty, false otherwise this.isEmpty = function() { return this.list().length > 0? false: true; }; // returns the elements of the set as a list this.list = function() { var arr = []; if (this.isNullAdded) arr.push(null); for (o in map) { // protect from inherited properties such as // Object.prototype.test = 'inherited property'; if (map.hasOwnProperty(o)) arr.push(o); } return arr; }; };