Class EmberArray

public
Uses: Enumerable
Defined in: packages/@ember/-internals/runtime/lib/mixins/array.js:185
Module: @ember/array
Since: vEmber 0.9.0 
import EmberArray from '@ember/array';

This mixin implements Observer-friendly Array-like behavior. It is not a concrete implementation, but it can be used up by other classes that want to appear like arrays.

For example, ArrayProxy is a concrete class that can be instantiated to implement array-like behavior. This class uses the Array Mixin by way of the MutableArray mixin, which allows observable changes to be made to the underlying array.

This mixin defines methods specifically for collections that provide index-ordered access to their contents. When you are designing code that needs to accept any kind of Array-like object, you should use these methods instead of Array primitives because these will properly notify observers of changes to the array.

Although these methods are efficient, they do add a layer of indirection to your application so it is a good idea to use them only when you need the flexibility of using both true JavaScript arrays and "virtual" arrays such as controllers and collections.

You can use the methods defined in this module to access and modify array contents in an observable-friendly way. You can also be notified whenever the membership of an array changes by using .observes('myArray.[]').

To support EmberArray in your own class, you must override two primitives to use it: length() and objectAt().

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[] public

Module: @ember/array

Defined in packages/@ember/-internals/runtime/lib/mixins/array.js:278

returns

this

This is the handler for the special array content property. If you get this property, it will return this. If you set this property to a new array, it will replace the current content.

let peopleToMoon = ['Armstrong', 'Aldrin'];

peopleToMoon.get('[]'); // ['Armstrong', 'Aldrin']

peopleToMoon.set('[]', ['Collins']); // ['Collins']
peopleToMoon.get('[]'); // ['Collins']

firstObject Object | undefined public

Module: @ember/array

Defined in packages/@ember/-internals/runtime/lib/mixins/array.js:306

returns
Object | undefined

The first object in the array

The first object in the array, or undefined if the array is empty.

let vowels = ['a', 'e', 'i', 'o', 'u'];
vowels.firstObject; // 'a'

vowels.shiftObject();
vowels.firstObject; // 'e'

vowels.reverseObjects();
vowels.firstObject; // 'u'

vowels.clear();
vowels.firstObject; // undefined

hasArrayObservers public

Module: @ember/array

Defined in packages/@ember/-internals/runtime/lib/mixins/array.js:552

Becomes true whenever the array currently has observers watching changes on the array.

let arr = [1, 2, 3, 4, 5];
arr.hasArrayObservers; // false

arr.addArrayObserver(this, {
  willChange() {
    console.log('willChange');
  }
});
arr.hasArrayObservers; // true

lastObject Object | undefined public

Module: @ember/array

Defined in packages/@ember/-internals/runtime/lib/mixins/array.js:331

returns
Object | undefined

The last object in the array

The last object in the array, or undefined if the array is empty.

length public

Module: @ember/array

Defined in packages/@ember/-internals/runtime/lib/mixins/array.js:224

Required. You must implement this method to apply this mixin.

Your array must support the length property. Your replace methods should set this property whenever it changes.