# collections-x > ES6 collections fallback library: Map and Set. Latest version **3.1.2** (published 2019-08-28) · MIT license · 0 weekly downloads ## Install ```sh npm install collections-x pnpm add collections-x yarn add collections-x bun add collections-x ``` ## Health **Score 20/100 (F)** — status: abandoned. Positive: esm support; no vulnerabilities. Warnings: low downloads; no types. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 3.1.2 | | Published | 2019-08-28 | | First published | 2015-11-30 | | Weekly downloads | 0 | | License | MIT | | TypeScript types | none | | Module format | ESM + CommonJS | | Node | >=8.11.4 | | Dependencies | 28 | | Unpacked size | 982 KB | | Known vulnerabilities | 0 | | Install scripts | no | | GitHub stars | 2 | | Author | Graham Fairweather | | Maintainers | xotic750 | | Keywords | es6, Map, Set, library, javascript, nodejs, browser | ## Links - npm: https://www.npmjs.com/package/collections-x - Repository: https://github.com/Xotic750/collections-x - Issues: https://github.com/Xotic750/collections-x/issues - npm.io page: https://npm.io/package/collections-x ## Dependencies (28) - [is-map-x](https://npm.io/package/is-map-x.md) ^2.1.2 - [is-set-x](https://npm.io/package/is-set-x.md) ^2.1.2 - [attempt-x](https://npm.io/package/attempt-x.md) ^2.1.2 - [is-string](https://npm.io/package/is-string.md) ^1.0.4 - [index-of-x](https://npm.io/package/index-of-x.md) ^3.1.2 - [is-array-x](https://npm.io/package/is-array-x.md) ^2.1.2 - [array-some-x](https://npm.io/package/array-some-x.md) ^3.1.2 - [to-boolean-x](https://npm.io/package/to-boolean-x.md) ^2.1.1 - [big-counter-x](https://npm.io/package/big-counter-x.md) ^4.1.2 - [is-function-x](https://npm.io/package/is-function-x.md) ^4.1.2 - [simple-call-x](https://npm.io/package/simple-call-x.md) ^1.0.3 - [is-primitive-x](https://npm.io/package/is-primitive-x.md) ^1.0.1 - [is-array-like-x](https://npm.io/package/is-array-like-x.md) ^2.1.2 - [object-create-x](https://npm.io/package/object-create-x.md) ^3.1.2 - [array-for-each-x](https://npm.io/package/array-for-each-x.md) ^3.1.2 - [is-object-like-x](https://npm.io/package/is-object-like-x.md) ^2.1.2 - [symbol-species-x](https://npm.io/package/symbol-species-x.md) ^1.1.2 - [is-boolean-object](https://npm.io/package/is-boolean-object.md) ^1.0.0 - [rename-function-x](https://npm.io/package/rename-function-x.md) ^1.1.2 - [symbol-iterator-x](https://npm.io/package/symbol-iterator-x.md) ^1.1.2 - [assert-is-object-x](https://npm.io/package/assert-is-object-x.md) ^3.1.2 - [get-prototype-of-x](https://npm.io/package/get-prototype-of-x.md) ^2.1.2 - [has-own-property-x](https://npm.io/package/has-own-property-x.md) ^4.1.2 - [simple-methodize-x](https://npm.io/package/simple-methodize-x.md) ^1.0.4 - [is-surrogate-pair-x](https://npm.io/package/is-surrogate-pair-x.md) ^3.1.2 - [assert-is-function-x](https://npm.io/package/assert-is-function-x.md) ^3.1.2 - [object-define-property-x](https://npm.io/package/object-define-property-x.md) ^5.1.2 - [object-define-properties-x](https://npm.io/package/object-define-properties-x.md) ^5.1.2 ## Alternatives - [@opentelemetry/exporter-zipkin](https://npm.io/package/@opentelemetry/exporter-zipkin.md) — 14.8M weekly downloads - [pusher-js](https://npm.io/package/pusher-js.md) — 2.0M weekly downloads - [browserify](https://npm.io/package/browserify.md) — 1.7M weekly downloads - [sqs-consumer](https://npm.io/package/sqs-consumer.md) — 1.7M weekly downloads - [@sanity/eventsource](https://npm.io/package/@sanity/eventsource.md) — 930.8K weekly downloads ## Recent versions - 3.1.2 (latest) — 2019-08-28 - 3.1.1 — 2019-08-20 - 3.1.0 — 2019-08-14 - 3.0.18 — 2019-08-05 - 3.0.17 — 2019-08-05 - 3.0.16 — 2019-08-05 - 3.0.15 — 2019-08-05 - 3.0.14 — 2019-08-05 - 3.0.13 — 2019-07-31 - 3.0.12 — 2019-07-27 - 3.0.11 — 2019-07-27 - 3.0.10 — 2019-07-26 - 3.0.9 — 2019-07-25 - 3.0.8 — 2019-07-24 - 3.0.7 — 2019-07-24 - … 30 more at https://npm.io/package/collections-x/versions ## README Travis status Dependency status devDependency status npm version jsDelivr hits bettercodehub score Coverage Status ## collections-x ES6 collections fallback library: Map and Set. - [collections-x](#module_collections-x) - [`.isMap`](#module_collections-x.isMap) ⇒ boolean - [`.isSet`](#module_collections-x.isSet) ⇒ boolean - [`.MapConstructor`](#module_collections-x.MapConstructor) - [`.clear`](#module_collections-x.MapConstructor+clear) ⇒ Object - [`.delete`](#module_collections-x.MapConstructor+delete) ⇒ boolean - [`.entries`](#module_collections-x.MapConstructor+entries) ⇒ Object - [`.forEach`](#module_collections-x.MapConstructor+forEach) ⇒ Object - [`.get`](#module_collections-x.MapConstructor+get) ⇒ \* - [`.keys`](#module_collections-x.MapConstructor+keys) ⇒ Object - [`.set`](#module_collections-x.MapConstructor+set) ⇒ Object - [`.size`](#module_collections-x.MapConstructor+size) : number - [`.values`](#module_collections-x.MapConstructor+values) ⇒ Object - [`.has(key)`](#module_collections-x.MapConstructor+has) ⇒ boolean - [`.symIt()`](#module_collections-x.MapConstructor+symIt) ⇒ Object - [`.SetConstructor`](#module_collections-x.SetConstructor) - [`.add`](#module_collections-x.SetConstructor+add) ⇒ Object - [`.clear`](#module_collections-x.SetConstructor+clear) ⇒ Object - [`.delete`](#module_collections-x.SetConstructor+delete) ⇒ boolean - [`.forEach`](#module_collections-x.SetConstructor+forEach) ⇒ Object - [`.size`](#module_collections-x.SetConstructor+size) : number - [`.entries()`](#module_collections-x.SetConstructor+entries) ⇒ Object - [`.has(value)`](#module_collections-x.SetConstructor+has) ⇒ boolean - [`.keys()`](#module_collections-x.SetConstructor+keys) ⇒ Object - [`.values()`](#module_collections-x.SetConstructor+values) ⇒ Object - [`.symIt()`](#module_collections-x.SetConstructor+symIt) ⇒ Object - [`.symIt`](#module_collections-x.symIt) ### `collections-x.isMap` ⇒ boolean Determine if an `object` is a `Map`. **Kind**: static property of [collections-x](#module_collections-x) **Returns**: boolean - `true` if the `object` is a `Map`, else `false`. | Param | Type | Description | | ------ | --------------- | ------------------- | | object | \* | The object to test. | **Example** ```js import {isMap} from 'collections-x'; const m = new MapConstructor(); console.log(isMap([])); // false console.log(isMap(true)); // false console.log(isMap(m)); // true ``` ### `collections-x.isSet` ⇒ boolean Determine if an `object` is a `Set`. **Kind**: static property of [collections-x](#module_collections-x) **Returns**: boolean - `true` if the `object` is a `Set`, else `false`. | Param | Type | Description | | ------ | --------------- | ------------------- | | object | \* | The object to test. | **Example** ```js import {isSet} from 'collections-x'; const s = new SetConstructor(); console.log(isSet([])); // false console.log(isSet(true)); // false console.log(isSet(s)); // true ``` ### `collections-x.MapConstructor` **Kind**: static property of [collections-x](#module_collections-x) - [`.MapConstructor`](#module_collections-x.MapConstructor) - [`.clear`](#module_collections-x.MapConstructor+clear) ⇒ Object - [`.delete`](#module_collections-x.MapConstructor+delete) ⇒ boolean - [`.entries`](#module_collections-x.MapConstructor+entries) ⇒ Object - [`.forEach`](#module_collections-x.MapConstructor+forEach) ⇒ Object - [`.get`](#module_collections-x.MapConstructor+get) ⇒ \* - [`.keys`](#module_collections-x.MapConstructor+keys) ⇒ Object - [`.set`](#module_collections-x.MapConstructor+set) ⇒ Object - [`.size`](#module_collections-x.MapConstructor+size) : number - [`.values`](#module_collections-x.MapConstructor+values) ⇒ Object - [`.has(key)`](#module_collections-x.MapConstructor+has) ⇒ boolean - [`.symIt()`](#module_collections-x.MapConstructor+symIt) ⇒ Object #### `map.clear` ⇒ Object The clear() method removes all elements from a Map object. **Kind**: instance property of [Map](#module_collections-x.MapConstructor) **Returns**: Object - The Map object. **Example** ```js import {MapConstructor} from 'collections-x'; const myMap = new MapConstructor(); myMap.set('bar', 'baz'); myMap.set(1, 'foo'); console.log(myMap.size); // 2 console.log(myMap.has('bar')); // true myMap.clear(); console.log(myMap.size); // 0 console.log(myMap.has('bar')); // false ``` #### `map.delete` ⇒ boolean The delete() method removes the specified element from a Map object. **Kind**: instance property of [Map](#module_collections-x.MapConstructor) **Returns**: boolean - Returns true if an element in the Map object has been removed successfully. | Param | Type | Description | | ----- | --------------- | ----------------------------------------------------- | | key | \* | The key of the element to remove from the Map object. | **Example** ```js import {MapConstructor} from 'collections-x'; const myMap = new MapConstructor(); myMap.set('bar', 'foo'); myMap.delete('bar'); // Returns true. Successfully removed. myMap.has('bar'); // Returns false. // The "bar" element is no longer present. ``` #### `map.entries` ⇒ Object The entries() method returns a new Iterator object that contains the [key, value] pairs for each element in the Map object in insertion order. **Kind**: instance property of [Map](#module_collections-x.MapConstructor) **Returns**: Object - A new Iterator object. **Example** ```js import {MapConstructor} from 'collections-x'; const myMap = new MapConstructor(); myMap.set('0', 'foo'); myMap.set(1, 'bar'); myMap.set({}, 'baz'); const mapIter = myMap.entries(); console.log(mapIter.next().value); // ["0", "foo"] console.log(mapIter.next().value); // [1, "bar"] console.log(mapIter.next().value); // [Object, "baz"] ``` #### `map.forEach` ⇒ Object The forEach() method executes a provided function once per each key/value pair in the Map object, in insertion order. **Kind**: instance property of [Map](#module_collections-x.MapConstructor) **Returns**: Object - The Map object. | Param | Type | Description | | --------- | --------------------- | --------------------------------------------- | | callback | function | Function to execute for each element. | | [thisArg] | \* | Value to use as this when executing callback. | **Example** ```js import {MapConstructor} from 'collections-x'; function logElements(value, key, map) { console.log('m[' + key + '] = ' + value); } const myMap = new MapConstructor([['foo', 3], ['bar', {}], ['baz', undefined]]); myMap.forEach(logElements); // logs: // "m[foo] = 3" // "m[bar] = [object Object]" // "m[baz] = undefined" ``` #### `map.get` ⇒ \* The get() method returns a specified element from a Map object. **Kind**: instance property of [Map](#module_collections-x.MapConstructor) **Returns**: \* - Returns the element associated with the specified key or undefined if the key can't be found in the Map object. | Param | Type | Description | | ----- | --------------- | ----------------------------------------------------- | | key | \* | The key of the element to return from the Map object. | **Example** ```js import {MapConstructor} from 'collections-x'; const myMap = new MapConstructor(); myMap.set('bar', 'foo'); myMap.get('bar'); // Returns "foo". myMap.get('baz'); // Returns undefined. ``` #### `map.keys` ⇒ Object The keys() method returns a new Iterator object that contains the keys for each element in the Map object in insertion order. **Kind**: instance property of [Map](#module_collections-x.MapConstructor) **Returns**: Object - A new Iterator object. **Example** ```js import {MapConstructor} from 'collections-x'; const myMap = new MapConstructor(); myMap.set('0', 'foo'); myMap.set(1, 'bar'); myMap.set({}, 'baz'); const mapIter = myMap.keys(); console.log(mapIter.next().value); // "0" console.log(mapIter.next().value); // 1 console.log(mapIter.next().value); // Object ``` #### `map.set` ⇒ Object The set() method adds a new element with a specified key and value to a Map object. **Kind**: instance property of [Map](#module_collections-x.MapConstructor) **Returns**: Object - The Map object. | Param | Type | Description | | ----- | --------------- | -------------------------------------------------- | | key | \* | The key of the element to add to the Map object. | | value | \* | The value of the element to add to the Map object. | **Example** ```js import {MapConstructor} from 'collections-x'; const myMap = new MapConstructor(); // Add new elements to the map myMap.set('bar', 'foo'); myMap.set(1, 'foobar'); // Update an element in the map myMap.set('bar', 'fuuu'); ``` #### `map.size` : number The value of size is an integer representing how many entries the Map object has. **Kind**: instance property of [Map](#module_collections-x.MapConstructor) **Example** ```js import {MapConstructor} from 'collections-x'; const myMap = new MapConstructor(); myMap.set(1, true); myMap.set(5, false); myMap.set('some text', 1); console.log(myMap.size); // 3 ``` #### `map.values` ⇒ Object The values() method returns a new Iterator object that contains the values for each element in the Map object in insertion order. **Kind**: instance property of [Map](#module_collections-x.MapConstructor) **Returns**: Object - A new Iterator object. **Example** ```js import {MapConstructor} from 'collections-x'; const myMap = new MapConstructor(); myMap.set('0', 'foo'); myMap.set(1, 'bar'); myMap.set({}, 'baz'); const mapIter = myMap.values(); console.log(mapIter.next().value); // "foo" console.log(mapIter.next().value); // "bar" console.log(mapIter.next().value); // "baz" ``` #### `map.has(key)` ⇒ boolean The has() method returns a boolean indicating whether an element with the specified key exists or not. **Kind**: instance method of [Map](#module_collections-x.MapConstructor) **Returns**: boolean - Returns true if an element with the specified key exists in the Map object; otherwise false. | Param | Type | Description | | ----- | --------------- | -------------------------------------------------------------- | | key | \* | The key of the element to test for presence in the Map object. | **Example** ```js import {MapConstructor} from 'collections-x'; const myMap = new MapConstructor(); myMap.set('bar', 'foo'); myMap.has('bar'); // returns true myMap.has('baz'); // returns false ``` #### `map.symIt()` ⇒ Object The initial value of the @@iterator property is the same function object as the initial value of the entries property. **Kind**: instance method of [Map](#module_collections-x.MapConstructor) **Returns**: Object - A new Iterator object. **Example** ```js import {MapConstructor, symIt} from 'collections-x'; const myMap = new MapConstructor(); myMap.set('0', 'foo'); myMap.set(1, 'bar'); myMap.set({}, 'baz'); var mapIter = myMap[symIt](); console.log(mapIter.next().value); // ["0", "foo"] console.log(mapIter.next().value); // [1, "bar"] console.log(mapIter.next().value); // [Object, "baz"] ``` ### `collections-x.SetConstructor` **Kind**: static property of [collections-x](#module_collections-x) - [`.SetConstructor`](#module_collections-x.SetConstructor) - [`.add`](#module_collections-x.SetConstructor+add) ⇒ Object - [`.clear`](#module_collections-x.SetConstructor+clear) ⇒ Object - [`.delete`](#module_collections-x.SetConstructor+delete) ⇒ boolean - [`.forEach`](#module_collections-x.SetConstructor+forEach) ⇒ Object - [`.size`](#module_collections-x.SetConstructor+size) : number - [`.entries()`](#module_collections-x.SetConstructor+entries) ⇒ Object - [`.has(value)`](#module_collections-x.SetConstructor+has) ⇒ boolean - [`.keys()`](#module_collections-x.SetConstructor+keys) ⇒ Object - [`.values()`](#module_collections-x.SetConstructor+values) ⇒ Object - [`.symIt()`](#module_collections-x.SetConstructor+symIt) ⇒ Object #### `set.add` ⇒ Object The add() method appends a new element with a specified value to the end of a Set object. **Kind**: instance property of [Set](#module_collections-x.SetConstructor) **Returns**: Object - The Set object. | Param | Type | Description | | ----- | --------------- | ------------------------------------------------------------ | | value | \* | Required. The value of the element to add to the Set object. | **Example** ```js import {SetConstructor} from 'collections-x'; const mySet = new SetConstructor(); mySet.add(1); mySet.add(5).add('some text'); // chainable console.log(mySet); // Set [1, 5, "some text"] ``` #### `set.clear` ⇒ Object The clear() method removes all elements from a Set object. **Kind**: instance property of [Set](#module_collections-x.SetConstructor) **Returns**: Object - The Set object. **Example** ```js import {SetConstructor} from 'collections-x'; const mySet = new SetConstructor(); mySet.add(1); mySet.add('foo'); console.log(mySet.size); // 2 mySet.has('foo'); // true mySet.clear(); console.log(mySet.size); // 0 mySet.has('bar'); // false ``` #### `set.delete` ⇒ boolean The delete() method removes the specified element from a Set object. **Kind**: instance property of [Set](#module_collections-x.SetConstructor) **Returns**: boolean - Returns true if an element in the Set object has been removed successfully; otherwise false. | Param | Type | Description | | ----- | --------------- | ------------------------------------------------------- | | value | \* | The value of the element to remove from the Set object. | **Example** ```js import {SetConstructor} from 'collections-x'; const mySet = new SetConstructor(); mySet.add('foo'); mySet.delete('bar'); // Returns false. No "bar" element found //to be deleted. mySet.delete('foo'); // Returns true. Successfully removed. mySet.has('foo'); // Returns false. The "foo" element is no //longer present. ``` #### `set.forEach` ⇒ Object The forEach() method executes a provided function once per each value in the Set object, in insertion order. **Kind**: instance property of [Set](#module_collections-x.SetConstructor) **Returns**: Object - The Set object. | Param | Type | Description | | --------- | --------------------- | --------------------------------------------- | | callback | function | Function to execute for each element. | | [thisArg] | \* | Value to use as this when executing callback. | **Example** ```js function logSetElements(value1, value2, set) { console.log('s[' + value1 + '] = ' + value2); } new SetConstructor(['foo', 'bar', undefined]).forEach(logSetElements); // logs: // "s[foo] = foo" // "s[bar] = bar" // "s[undefined] = undefined" ``` #### `set.size` : number The value of size is an integer representing how many entries the Set object has. **Kind**: instance property of [Set](#module_collections-x.SetConstructor) **Example** ```js import {SetConstructor} from 'collections-x'; const mySet = new SetConstructor(); mySet.add(1); mySet.add(5); mySet.add('some text'); console.log(mySet.size); // 3 ``` #### `set.entries()` ⇒ Object The entries() method returns a new Iterator object that contains an array of [value, value] for each element in the Set object, in insertion order. For Set objects there is no key like in Map objects. However, to keep the API similar to the Map object, each entry has the same value for its key and value here, so that an array [value, value] is returned. **Kind**: instance method of [Set](#module_collections-x.SetConstructor) **Returns**: Object - A new Iterator object. **Example** ```js import {SetConstructor} from 'collections-x'; const mySet = new SetConstructor(); mySet.add('foobar'); mySet.add(1); mySet.add('baz'); const setIter = mySet.entries(); console.log(setIter.next().value); // ["foobar", "foobar"] console.log(setIter.next().value); // [1, 1] console.log(setIter.next().value); // ["baz", "baz"] ``` #### `set.has(value)` ⇒ boolean The has() method returns a boolean indicating whether an element with the specified value exists in a Set object or not. **Kind**: instance method of [Set](#module_collections-x.SetConstructor) **Returns**: boolean - Returns true if an element with the specified value exists in the Set object; otherwise false. | Param | Type | Description | | ----- | --------------- | ------------------------------------------------- | | value | \* | The value to test for presence in the Set object. | **Example** ```js import {SetConstructor} from 'collections-x'; const mySet = new SetConstructor(); mySet.add('foo'); mySet.has('foo'); // returns true mySet.has('bar'); // returns false ``` #### `set.keys()` ⇒ Object The keys() method is an alias for the `values` method (for similarity with Map objects); it behaves exactly the same and returns values of Set elements. **Kind**: instance method of [Set](#module_collections-x.SetConstructor) **Returns**: Object - A new Iterator object. **Example** ```js import {SetConstructor} from 'collections-x'; const mySet = new SetConstructor(); mySet.add('foo'); mySet.add('bar'); mySet.add('baz'); const setIter = mySet.keys(); console.log(setIter.next().value); // "foo" console.log(setIter.next().value); // "bar" console.log(setIter.next().value); // "baz" ``` #### `set.values()` ⇒ Object The values() method returns a new Iterator object that contains the values for each element in the Set object in insertion order. **Kind**: instance method of [Set](#module_collections-x.SetConstructor) **Returns**: Object - A new Iterator object. **Example** ```js import {SetConstructor} from 'collections-x'; const mySet = new SetConstructor(); mySet.add('foo'); mySet.add('bar'); mySet.add('baz'); const setIter = mySet.values(); console.log(setIter.next().value); // "foo" console.log(setIter.next().value); // "bar" console.log(setIter.next().value); // "baz" ``` #### `set.symIt()` ⇒ Object The initial value of the @@iterator property is the same function object as the initial value of the values property. **Kind**: instance method of [Set](#module_collections-x.SetConstructor) **Returns**: Object - A new Iterator object. **Example** ```js import {SetConstructor, symIt} from 'collections-x'; const mySet = new SetConstructor(); mySet.add('0'); mySet.add(1); mySet.add({}); const setIter = mySet[symIt](); console.log(setIter.next().value); // "0" console.log(setIter.next().value); // 1 console.log(setIter.next().value); // Object ``` ### `collections-x.symIt` The iterator identifier that is in use. type {Symbol|string} **Kind**: static property of [collections-x](#module_collections-x) --- _Source: https://npm.io/package/collections-x · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._