Map Or Similar

A JavaScript Map() or Similar() object polyfill if Map is not available. Supports complex objects for keys. Highly performant. No dependencies. Made for the browser and nodejs.

Install

npm install map-or-similar --save

Use

Supports the following methods and properties identically to Map():

set(key, val)     : Sets a value to a key. Key can be a complex object, array, etc.
get(key)          : Returns the value of a key.
has(key)          : Returns true if the key exists, otherwise false.
delete(key)       : Deletes a key and its value.
forEach(callback) : Invokes callback(val, key, object) once for each key-value pair in insertion order.
size              : Returns the number of keys-value pairs.

var MapOrSimilar = require('map-or-similar');
var mapOrSimilar = new MapOrSimilar();
var complexKey = { prop: 'a complex object as key' };

mapOrSimilar.set(complexKey, 'my value'); // sets value of complex key { prop: 'a complex object as key' } to 'my value'
mapOrSimilar.get(complexKey); // returns 'my value'
mapOrSimilar.has(complexKey); // returns true
mapOrSimilar.size // returns 1
mapOrSimilar.forEach((val, key) => { /* iterates once in this case, val is 'my value', key is { prop: 'a complex object as key' }*/ });
mapOrSimilar.delete(complexKey); // deletes key/value
mapOrSimilar.size // returns 0

Does not support other Map methods or properties.

Test

npm run test

License

Released under an MIT license.

Other Libs

• Memoizerific: Fastest, smallest, most-efficient JavaScript memoization lib to memoize JS functions.
• Multi Key Cache: A JavaScript (JS) cache that can have multiple complex values as keys.