Ember.js Ember.NativeArray clear() Method

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

export default class PartyRoute extends Route {
    partyItems = [
        'Oxygen',
        'Tenet',
        undefined,
        'Source Code',
        'Infine',
        'Loopert',
        'Tenet',
        undefined,
        'SpiderHead',
        'The Thing',
        undefined,
        'A Quiet Place',
        'The Invisible Man',
        'Looper',
        'The Thing',
        'Ad Astra',
        undefined,
    ];
    list = [
        'Shutter Island',
        'Matrix',
        'Avatar',
        'Fantastic Beast',
        'Avengers',
        'Fantastic four',
        'HulK',
        'Superman',
        'Spiderman',
        'The Batman'
    ];
    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);
        controller.set('list', this.list);
    }
}

import Ember from 'ember';
import { reverseObjects, unshiftObject, uniq, }
    from '@ember/array';

export default Ember.Controller.extend({
    actions: {
        delete() {
            this.partyItems.clear();

        },
        insert(data) {
            this.partyItems.addObject(data);
        },
        add() {
            this.partyItems.addObjects(this.list);
        },
        remove() {
            let res = this.partyItems.compact();
            this.partyItems.setObjects(res)
        },
        check(data) {
            let ans = this.partyItems.find((item) => item == data);
            alert(ans ? `${ans} present in list` : 
                `${data} not present in list`)
        }
    },
});

{{page-title "clear"}}
<h3>Here is a list of items: </h3>
<ul>
    {{#each @model as |party|}}
        <li>{{party}}</li>
    {{/each}}
</ul>
<br />
<div>
    <label>Enter Item: </label>
    {{input value=this.item}}
</div>
<div>
    <input
        type="button"
        id="insert-item"
        value="Insert item"
        {{action "insert" this.item }}
    />
</div>
<br />
<div>
    <label>Enter Item: </label>
    {{input value=this.item2}}
</div>
<div>
    <input
        type="button"
        id="check-item"
        value="check item"
        {{action "check" this.item2 }}
    />
</div>
<br />
<input 
    type="button"
    id="append-list"
    value="Append More Movies"
    {{action "add"}} />
    
<br />
<br />
<input 
    type="button"
    id="remove-undefined"
    value="Remove undefined"
    {{action "remove"}} />
    
<br />
<br/>
<input 
    type="button"
    id="del_list"
    value="Delete All"
    {{action "delete"}} />
{{outlet}}

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

export default class ListRoute extends Route {
    list = [
        "Digital Camera",
        "Speakers",
        "Balloons",
        "Scissors",
        null,
        "Table Confetti",
        null,
        "Wine",
        "Napkins",
        "Party Plates",
        null,
        "Music System",
        "Cups",];
    list2 = [
        "Laptop",
        "Bad",
        "Head Phone",
        "Bluetooth",
        'Phone',
        'Shoes',
    ]
    item;
    idx;
    model() {
        return this.list;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('list', this.list);
        controller.set('list2', this.list2);
        controller.set('item', this.item);
        controller.set('idx', this.idx);
    }
}

import Ember from 'ember';
import { reverseObjects, uniq, setObjects, unshiftObject }
    from '@ember/array';

export default Ember.Controller.extend({
    actions: {
        clear() {
            this.list.clear();
        },
        remove_null() {
            let k = this.list.compact();
            this.list.setObjects(k);
        },
        add_item(item) {
            this.list.addObject(item);
        },
        Add_list() {
            this.list.addObjects(this.list2);
        },
        check_item(data) {
            let ans = this.list.find((item) => item == data);
            alert(ans ? `${ans} is present in list` : 
                `${data} is not present in list`);
        },
    },
});

{{page-title "clear"}}
<h3>Here is a list of Items: </h3>
<ul>
    {{#each @model as |i|}}
        <li>{{i}}</li>
      {{/each}}
</ul>
<br />
<div>
    <label>Enter Item: </label>
      {{input value=this.item2}}
</div>
<div>
    <input
        type="button"
        id="check-item"
        value="Check Item"
        {{action "check_item" this.item2}}
      />
</div>
<br />
<div>
    <label>Enter Item: </label>
      {{input value=this.item}}
</div>
<div>
    <input
        type="button"
        id="insert-item"
        value="Insert Item"
        {{action "add_item" this.item}}
      />
</div>
<br />
<input
    type="button"
      id="append-list"
      value="Append More Items"
      {{action "Add_list"}}
/>
<br /><br />
<input
    type="button"
      id="reverse_list"
      value="Remove null"
      {{action "remove_null"}}
/>
<br /><br />
<input 
    type="button" 
    id="clear" 
    value="Clear" 
    {{action "clear"}} />
{{outlet}}