Ember.js MutableArray includes() Method

Ember.js is an open-source JavaScript framework used for developing large client-side web applications which is based on Model-View-Controller (MVC) architecture. Ember.js is one of the most widely used front-end application frameworks. It is made to speed up development and increase productivity. Currently, it is utilized by a large number of websites, including Square, Discourse, Groupon, Linked In, Live Nation, Twitch, and Chipotle.

The includes()  method is used to check if a given object is present in the array or not.

Syntax:

includes(obj,startAt)

Parameters:

• obj: The object to find.
• startAt: The optional starting index to search from.

Returns: True if the array contains the object, else false.

Step 1: To run the following examples you will need to have an ember project with you. To create one, you will need to install ember-cli first. Write the below code in the terminal:

npm install ember-cli

Now you can create the project by typing in the following piece of code:

ember new <project-name> --lang en

Step 2: To start the server, type:

ember serve

Example 1: Type the following code to generate the route for this example:

ember generate route list

app/routes/list.js

import Route from '@ember/routing/route';

export default class ListRoute extends Route {
    list = ['a', 'a', 'v', 'c', 'c', 'a', 'd',
        'q', 'b', 'z', 'a'];
    item;
    idx;
    model() {
        return this.list;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('list', this.list);
        controller.set('item', this.item);
        controller.set('idx', this.idx);
    }
}

app/controllers/list.js

import Ember from 'ember';
import { clear, insertAt, indexOf, lastIndexOf, includes }
    from '@ember/array';

export default Ember.Controller.extend({
    actions: {
        insertItem(item, idx) {
            this.list.insertAt(idx, item);
        },
        getLastIndex(item) {
            let res = this.list.lastIndexOf(item);
            alert(res);
        },
        getFirstIndex(item) {
            let res = this.list.indexOf(item);
            alert(res);
        },
        clearList() {
            this.list.clear();
        },
        contains(item) {
            let res = this.list.includes(item);
            alert(`The list ${res ? '' : 'does not'}
            contains ${item}`);
        },
    },
});

app/template/list.hbs

{{page-title "List"}}
<h3>Here is a list of Items: </h3>
<ul>
    {{#each @model as |i|}}
        <li>{{i}}</li>
      {{/each}}
</ul>
<br /><br />
<div>
    <label>Enter Item: </label>
      {{input value=this.item}}
</div>
<div>
    <label>Enter Index: </label>
      {{input value=this.idx}}
</div>
<div>
    <input
        type="button"
        id="insert-item"
        value="Insert Item"
        {{action "insertItem" this.item this.idx}}
      />
</div>
<br /><br />
<div>
    <label>Enter Item: </label>
      {{input value=this.item}}
</div>
<div>
    <input
        type="button"
        id="first-index-item"
        value="Get First Index"
        {{action "getFirstIndex" this.item}}
      />
</div>
<div>
    <input
        type="button"
        id="last-index-item"
        value="Get Last Index"
        {{action "getLastIndex" this.item}}
      />
</div>
<div>
    <input
        type="button"
        id="contains-item"
        value="Contains?"
        {{action "contains" this.item}}
      />
</div>
<br /><br />
<input type="button" id="clear-items" value="Clear"
    {{action "clearList"}} />
{{outlet}}

Output: Visit localhost:4200/list to view the output

Example 2: Type the following code to generate the route for this example:

ember generate route party

app/routes/party.js

import Route from '@ember/routing/route';

export default class PartyRoute extends Route {
    partyItems = [
        'Digital Camera',
        'Jugs, cups & straws',
        'Cold Drink',
        'Balloons',
        'Scissors',
        'Wine',
        'Cold Drink',
        'Table Confetti',
        'Party Hats',
        'Wine',
        'Napkins',
        'Party Plates',
        'Speakers',
        'Wine',
        'Music System',
        'Cold Drink',
        'Cups',
    ];
    item;
    idx;
    model() {
        return this.partyItems;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('partyItems', this.partyItems);
        controller.set('item', this.item);
        controller.set('idx', this.idx);
    }
}

app/controllers/party.js

import Ember from 'ember';
import { insertAt, indexOf, lastIndexOf, includes }
    from '@ember/array';

export default Ember.Controller.extend({
    actions: {
        insertItem(item, idx) {
            this.partyItems.insertAt(idx, item);
        },
        getLastIndex(item) {
            let res = this.partyItems.lastIndexOf(item);
            alert(res);
        },
        getFirstIndex(item) {
            let res = this.partyItems.indexOf(item);
            alert(res);
        },
        clearpartyItems() {
            this.partyItems.clear();
        },
        contains(item) {
            let res = this.partyItems.includes(item);
            alert(`The partyItems ${res ? '' : 'does not'}
            contains ${item}`);
        },
    },
});

app/template/party.hbs

{{page-title "Party"}}
<h3>Here is a list of items: </h3>
<ul>
    {{#each @model as |party|}}
        <li>{{party}}</li>
      {{/each}}
</ul>
<br /><br />
<div>
    <label>Enter Item: </label>
      {{input value=this.item}}
</div>
<div>
    <label>Enter Index: </label>
      {{input value=this.idx}}
</div>
<div>
    <input
        type="button"
        id="insert-item"
        value="Insert Item"
        {{action "insertItem" this.item this.idx}}
      />
</div>
<br /><br />
<div>
    <label>Enter Item: </label>
      {{input value=this.item}}
</div>
<div>
    <input
        type="button"
        id="first-index-item"
        value="Get First Index"
        {{action "getFirstIndex" this.item}}
      />
</div>
<div>
    <input
          type="button"
        id="last-index-item"
        value="Get Last Index"
        {{action "getLastIndex" this.item}}
      />
</div>
<div>
    <input
        type="button"
        id="contains-item"
        value="Contains?"
        {{action "contains" this.item}}
      />
</div>
<br /><br />
{{outlet}}

Output: Visit localhost:4200/party to view the output

Reference: https://api.emberjs.com/ember/4.4/classes/MutableArray/methods