Ember.js EmberArray slice() 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 slice() method is used to return a new array that is a portion of the receiver.

Syntax:

slice(begin,end)

Parameters:

• begin: Starting index.
• end: Ending index.

Returns: Portion of the receiver between begin and end.

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

Step 2: Now you can create the project by typing in the following piece of code:

ember new <project-name> --lang en

To start the server, type:

ember serve

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

ember generate route details

app/routes/details.js

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

export default class DetailsRoute extends Route {
    details = [
        {
            name: 'Anubhav',
            mobile: '1298119967',
            city: 'Patna',
            country: 'India',
            gender: 'M',
            zipCode: '800020',
        },
        {
            name: 'Sakshi',
            mobile: '1234567890',
            city: 'Mumbai',
            country: 'India',
            gender: 'F',
            zipCode: '400001',
        },
        {
            name: 'Satyam',
            mobile: '2222222222',
            city: 'Delhi',
            country: 'India',
            gender: 'M',
            zipCode: '110012',
        },
        {
            name: 'Shivam',
            mobile: '1122113322',
            city: 'Patna',
            country: 'India',
            gender: 'M',
            zipCode: '530068',
        },
        {
            name: 'Ayushi',
            mobile: '2244668800',
            city: 'Jaipur',
            country: 'India',
            gender: 'F',
            zipCode: '302001',
        },
    ];
    someMoreDetails = [
        {
            name: 'Yeshwant',
            mobile: '1133557799',
            city: 'Chennai',
            country: 'India',
            gender: 'M',
            zipCode: '600001',
        },
        {
            name: 'Siddhant',
            mobile: '9911000000',
            city: 'Mangalore',
            country: 'India',
            gender: 'M',
            zipCode: '574142',
        },
        {
            name: 'Khushi',
            mobile: '8888888888',
            city: 'Pune',
            country: 'India',
            gender: 'F',
            zipCode: '111045',
        },
    ];
    city;
    start;
    end;
    model() {
        return this.details;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('details', this.details);
        controller.set('someMoreDetails', this.someMoreDetails);
        controller.set('city', this.city);
        controller.set('start', this.start);
        controller.set('end', this.end);
    }
}

app/controllers/details.js

import Ember from "ember";
import { any, slice, reverseObjects,
    rejectBy } from "@ember/array";

export default Ember.Controller.extend({
    actions: {
        checkCity(city) {
            let res = this.details.any((person) =>
            person.city == city);
            alert(`Present: ${res ? "YES" : "NO"}`);
        },
        sliceItems(start, end) {
            let tempItems = this.details.slice(start, end);
            let str = "";
            for (let i = 0; i < tempItems.length; i++)
                str += tempItems[i].name + "\n";
            alert(str);
        },
        reverse() {
            this.set("details",
            this.details.reverseObjects());
        },
        getFemale() {
            let tempItems =
                this.details.rejectBy("gender", "M");
            let str = "";
            for (let i = 0; i < tempItems.length; i++)
                str += tempItems[i].name + "\n";
            alert(str);
        },
        pushMoreDetails() {
            this.details.pushObjects(this.someMoreDetails);
        },
    },
});

app/template/details.hbs

{{page-title "Details"}}
<h3>List of People: </h3>
<br /><br />
<table>
    <tr>
        <th>Name</th>
        <th>Gender</th>
        <th>Mobile</th>
        <th>City</th>
        <th>Country</th>
        <th>Zip Code</th>
    </tr>
    {{#each @model as |detail|}}
    <tr>
          <td>{{detail.name}}</td>
          <td>{{detail.gender}}</td>
          <td>{{detail.mobile}}</td>
          <td>{{detail.city}}</td>
          <td>{{detail.country}}</td>
          <td>{{detail.zipCode}}</td>
    </tr>
      {{/each}}
</table>
<br /><br />
<div>
    <label>Enter City: </label>
      {{input value=this.city}}
</div>
<div>
    <input
        type="button"
        id="check-city"
        value="Check"
        {{action "checkCity" this.city}}
    />
</div>
<br /><br />
<div>
    <label>Enter Start Index: </label>
      {{input value=this.start}}
</div>
<div>
    <label>Enter End Index: </label>
      {{input value=this.end}}
</div>
<div>
    <input
        type="button"
        id="slice-items"
        value="Slice Items"
        {{action "sliceItems" this.start this.end}}
    />
</div>
<br /><br />
<input
    type="button"
    id="push-details"
    value="Add More Details"
    {{action "pushMoreDetails"}}
/>
<br /><br />
<input type="button" id="reverse" value="Reverse"
    {{action "reverse"}} />
<br /><br />
<input
    type="button"
    id="get-female"
    value="Get Female"
    {{action "getFemale"}}
/>

Output: Visit localhost:4200/details 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',
        'Balloons',
        'Scissors',
        'Cold Drink',
        'Table Confetti',
        'Party Hats',
        'Wine',
        'Napkins',
        'Party Plates',
        'Speakers',
        'Music System',
        'Cups',
    ];
    itemString;
    itemList;
    start;
    end;
    helper(itemString) {
        this.itemList = itemString.split(',');
        for (let i = 0; i < this.itemList.length; i++)
            this.itemList[i] = this.itemList[i].trim();
        return this.itemList;
    }
    model() {
        return this.partyItems;
    }
    setupController(controller, model) {
        this._super(controller, model);
        controller.set('helper', this.helper);
        controller.set('partyItems', this.partyItems);
        controller.set('itemString', this.itemString);
        controller.set('itemList', this.itemList);
        controller.set('start', this.start);
        controller.set('end', this.end);
    }
}

app/controllers/party.js

import Ember from "ember";
import {
    objectsAt,
    removeObject,
    removeObjects,
    slice,
    reverseObjects,
    setObjects,
    reject,
} from "@ember/array";

export default Ember.Controller.extend({
    actions: {
        getItems(itemString) {
            this.itemList = this.helper(itemString);
            for (let i = 0; i < this.itemList.length; i++)
                this.itemList[i] =
                parseInt(this.itemList[i]);
            let tempItems =
                this.partyItems.objectsAt(this.itemList);
            let str = "";
            for (let i = 0; i < tempItems.length; i++)
                str += tempItems[i] + "\n";
            alert(str);
        },
        removeItems(itemString) {
            this.itemList = this.helper(itemString);
            if (this.itemList.length == 1)
                this.partyItems.removeObject(this.itemList[0]);
            else this.partyItems.removeObjects(this.itemList);
            this.set("itemString", "");
        },
        sliceItems(start, end) {
            let tempItems = this.partyItems.slice(start, end);
            let str = "";
            for (let i = 0; i < tempItems.length; i++)
                str += tempItems[i] + "\n";
            alert(str);
        },
        reverseItems() {
            this.set("partyItems",
                this.partyItems.reverseObjects());
        },
        replaceItems(itemString) {
            this.partyItems.setObjects(this.helper(itemString));
        },
        findMultiwordItems() {
            let reqItem = this.partyItems.reject(
                (item) => item.split(" ").toArray().length == 1
            );
            alert(reqItem);
        },
    },
});

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 Items: </label>
          {{input value=this.itemString}}
</div>
<div>
    <input
        type="button"
        id="remove-item"
        value="Remove Items"
        {{action "removeItems" this.itemString}}
      />
</div>
<br /><br />
<div>
    <label>Enter Start Index: </label>
        {{input value=this.start}}
</div>
<div>
    <label>Enter End Index: </label>
          {{input value=this.end}}
</div>
<div>
    <input
        type="button"
        id="slice"
        value="Slice"
        {{action "sliceItems" this.start this.end}}
  />
</div>
<br /><br />
<div>
    <label>Enter Indices: </label>
          {{input value=this.itemString}}
</div>
<div>
    <input
        type="button"
        id="get-item"
        value="Get Items"
        {{action "getItems" this.itemString}}
      />
</div>
<br /><br />
<div>
    <label>Enter Items: </label>
          {{input value=this.itemString}}
</div>
<div>
    <input
        type="button"
        id="replace-item"
        value="Replace Items"
        {{action "replaceItems" this.itemString}}
      />
</div>
<br /><br />
<input
    type="button"
      id="reverse-items"
      value="Reverse"
      {{action "reverseItems"}}
/>
<br /><br />
<input
    type="button"
    id="find-items"
    value="Find"
    {{action "findMultiwordItems"}}
/>

{{outlet}}

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

Reference: https://api.emberjs.com/ember/4.6/classes/EmberArray/methods/