Ember.js Ember.NativeArray find()方法

Ember.js 是一个用于开发大型客户端网页应用程序的开源JavaScript框架，它基于模型-视图-控制器（MVC）架构。Ember.js 是最广泛使用的前端应用程序框架之一。它旨在加快开发速度和提高生产力。目前，许多网站都在使用Ember.js，包括Square、Discourse、Groupon、LinkedIn、Live Nation、Twitch和Chipotle等。

find() 方法用于获取第一个满足回调函数返回真值的元素。

语法：

find( callback, target);

参数：

callback： 检查每个元素的回调函数。
target： 回调函数将执行的目标对象。

返回值： 找到的元素或undefined。

安装和运行Ember.js的步骤：

要运行以下示例，您需要拥有一个Ember项目。要创建一个，您需要首先安装ember-cli。在终端中写下以下代码：

npm install ember-cli

现在，您可以通过输入以下代码来创建项目：

ember new <project-name> --lang en

启动服务器，请输入：

ember server

示例1： 在下面的示例中，键入以下代码以生成路由：

ember generate route find1

app/routes/find1.js

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);
    }
}

app/controllers/find.js

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`)
        }
    },
});

app/templates/find1.hbs

{{page-title "find"}}
<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}}

输出： 访问 localhost:4200/find1 查看输出

Ember.js Ember.NativeArray find()方法

示例2： 输入以下代码以生成此示例的路由：

ember generate route find2

app/routes/find2.js

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);
    }
}

app/controllers/find2.js

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`);
        },
    },
});

app/templates/find2.hbs

{{page-title "find"}}
<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}}