Map.md

Map

An implementation analogous to the Map specification in ES2015, with the exception of iterators. The entries, keys, and values methods are omitted, since forEach essentially provides the same functionality.

Creation

Empty Map

import { Map } from '@dojo/shim/Map';

var map = new Map();

With Initial Values

import { Map } from '@dojo/shim/Map';

var map = new Map([
	['age', 2],
	['height', 1.5]
]);

Adding a key/value pair

import { Map } from '@dojo/shim/Map';

var map = new Map([
	['age', 2],
	['height', 1.5]
]);

var key = 'weight';
var value = 14;

map.set(key, value);

Getting the amount of key/value pairs

import { Map } from '@dojo/shim/Map';

var map = new Map([
	['age', 2],
	['height', 1.5]
]);

map.size() === 2; // true

Clearing the key/value pairs

import { Map } from '@dojo/shim/Map';

var map = new Map([
	['age', 2],
	['height', 1.5]
]);

map.clear();

map.size() === 0; // true

Deleting a pair

import { Map } from '@dojo/shim/Map';

var map = new Map([
	['age', 2],
	['height', 1.5]
]);

var key = 'age';

map.delete(key);

map.size() === 1; // true

Loop over the key/value pairs

import { Map } from '@dojo/shim/Map';

var map = new Map([
	['age', 2],
	['height', 1.5]
]);

map.forEach((value, key, map) -> {
	console.log('key: ' + key + ' value: ' + value);
});

Retrieving a value

import { Map } from '@dojo/shim/Map';

var map = new Map([
	['age', 2],
	['height', 1.5]
]);

var key = 'age';

map.get(key) === 2; // true

Determine whether the map has a key

import { Map } from '@dojo/shim/Map';

var map = new Map([
	['age', 2],
	['height', 1.5]
]);

map.has('age'); // true
map.has('weight'); // false