Ember.js MutableArray clear() 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 clear() method removes all the elements in the array

Syntax:

clear()

Parameters: It doesn’t take any parameters.

Return Value: An empty array.

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",
            age: 20,
            salary: 10000,
            city: "Patna",
            country: "India",
            gender: "M",
            zipCode: "800020",
        },
        {
            name: "Sakshi",
            mobile: "1234567890",
            age: 17,
            salary: 2000,
            city: "Mumbai",
            country: "India",
            gender: "F",
            zipCode: "400001",
        },
        {
            name: "Satyam",
            mobile: "2222222222",
            age: 42,
            salary: 230000,
            city: "Delhi",
            country: "India",
            gender: "M",
            zipCode: "110012",
        },
        {
            name: "Shivam",
            mobile: "1122113322",
            age: 33,
            salary: 122200,
            city: "Patna",
            country: "India",
            gender: "M",
            zipCode: "530068",
        },
        {
            name: "Ayushi",
            mobile: "2244668800",
            age: 11,
            salary: 100,
            city: "Jaipur",
            country: "India",
            gender: "F",
            zipCode: "302001",
        },
        {
            name: "Yeshwant",
            mobile: "1133557799",
            age: 19,
            salary: 5000,
            city: "Chennai",
            country: "India",
            gender: "M",
            zipCode: "600001",
        },
        {
            name: "Siddhant",
            mobile: "9911000000",
            age: 65,
            salary: 992130,
            city: "Mangalore",
            country: "India",
            gender: "M",
            zipCode: "574142",
        },
        {
            name: "Khushi",
            mobile: "8888888888",
            age: 10,
            salary: 0,
            city: "Pune",
            country: "India",
            gender: "F",
            zipCode: "111045",
        },
    ];
    model() {
        return this.details;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set("details", this.details);
    }
}

app/controllers/details.js

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

export default Ember.Controller.extend({
    actions: {
        getAllNames() {
            let tempItems = this.details.getEach("name");
            let str = "";
            for (let i = 0; i < tempItems.length; i++)
                str += tempItems[i] + "\n";
            alert(str);
        },
        allAdult() {
            let res = this.details.every(
                (person) => person.age > 18);
            alert(`${res ? "YES" : "NO"}`);
        },
        getFemale() {
            let tempItems = this.details.filter(
                (person) => person.gender === "F");
            let str = "";
            for (let i = 0; i < tempItems.length; i++)
                str += tempItems[i].name + "\n";
            alert(str);
        },
        increaseSalary() {
            this.details.forEach(
                (person) => Ember.set(person, "salary",
                person.salary + 1000)
            );
        },
        hideNumber() {
            this.details.map((person) =>
                Ember.set(person, "mobile", "**********"));
        },
        clearAll() {
            this.details.clear();
        },
    },
});

app/template/details.hbs

{{page-title "Details"}}
<h3>List of People: </h3>
<br /><br />
<table>
    <tr>
        <th>Name</th>
        <th>Gender</th>
        <th>Age</th>
        <th>Salary</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.age}}</td>
        <td>{{detail.salary}}</td>
        <td>{{detail.mobile}}</td>
        <td>{{detail.city}}</td>
        <td>{{detail.country}}</td>
        <td>{{detail.zipCode}}</td>
    </tr>
    {{/each}}
</table>

<br /><br />
<input type="button" id="get-all"
    value="Get All Names"
    {{action "getAllNames" }} />
<br /><br />

<input type="button" id="get-all-adult"
    value="Is there only adult?"
    {{action "allAdult" }} />
<br /><br />

<input type="button" id="get-female"
    value="Get Female"
    {{action "getFemale" }} />
<br /><br />

<input type="button" id="increase-salary"
    value="Increase Salary"
    {{action "increaseSalary" }} />
<br /><br />

<input type="button" id="hide-number"
    value="Hide Number"
    {{action "hideNumber" }} />
<br /><br />

<input type="button" id="clear-all"
    value="Clear" {{action "clearAll" }} />

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 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

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