API Docs for: v2.11.0-beta.7
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Ember.Map Class

Module: ember-metal
Parent Module: ember

A Map stores values indexed by keys. Unlike JavaScript's default Objects, the keys of a Map can be any JavaScript object.

Internally, a Map has two data structures:

  1. keys: an OrderedSet of all of the existing keys
  2. values: a JavaScript Object indexed by the Ember.guidFor(key)

When a key/value pair is added for the first time, we add the key to the keys OrderedSet, and create or replace an entry in values. When an entry is deleted, we delete its entry in keys and values.

Constructor

Ember.Map

() private

Item Index

Properties

Methods

clear

() private

copy

() Ember.Map private

Returns:

create

() private static

delete

(
  • key
)
Boolean private

Defined in packages/ember-metal/lib/map.js:320

Available since 1.8.0

Removes a value from the map for an associated key.

Parameters:

  • key

Returns:

Boolean:

true if an item was removed, false otherwise

forEach

(
  • callback
  • self
)
private

Iterate over all the keys and values. Calls the function once for each key, passing in value, key, and the map being iterated over, in that order.

The keys are guaranteed to be iterated over in insertion order.

Parameters:

  • callback Function
  • self

    if passed, the this value inside the callback. By default, this is the map.

get

(
  • key
)
private

Retrieve the value associated with a given key.

Parameters:

  • key

Returns:

:

the value associated with the key, or undefined

has

(
  • key
)
Boolean private

Check whether a key is present.

Parameters:

  • key

Returns:

Boolean:

true if the item was present, false otherwise

set

(
  • key
  • value
)
Ember.Map private

Adds a value to the map. If a value for the given key has already been provided, the new value will replace the old value.

Parameters:

  • key
  • value

Returns:

Properties

size

Number private

Defined in packages/ember-metal/lib/map.js:265

Available since 1.8.0

This property will change as the number of objects in the map changes.

Default: 0