Embeer.js ArrayProxy lastIndexOf()用法及代码示例

Ember.js 是一个开源 JavaScript 框架，用于开发基于 Model-View-Controller (MVC) 架构的大型客户端 Web 应用程序。 Ember.js是使用最广泛的前端应用框架之一。它的目的是加速开发并提高生产力。目前，它被大量网站使用，包括 Square、Discourse、Groupon、Linked In、Live Nation、Twitch 和 Chipotle。

lastIndexOf() 方法用于获取给定对象最后一次出现的索引。

用法:

lastIndexOf( object, startAt );

参数：

object: 这就是我们想要索引的对象。
startAt:这是搜索的起始位置。

返回值：数组中对象的最后一个索引；如果未找到，则返回 -1。

要运行以下示例，您需要有一个 ember 项目。要创建一个，您需要先安装ember-cli。在终端中写入以下代码：

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

要启动服务器，请键入：

ember serve

示例 1：键入以下代码以生成本示例的路由：

ember generate route lastIndexOf1

应用程序/路线/lastIndexOf1.js


import Route from '@ember/routing/route'; 
  
export default class ListRoute extends Route { 
    list = [1, 2, 3, 5, 6, 2, 1, 7, 8, 9, 8]; 
    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); 
    } 
}

应用程序/控制器/lastIndexOf1.js


import Ember from 'ember'; 
import { lastIndexOf, includes, addObject, clear } 
    from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        insertItem(item) { 
            this.list.addObject(item); 
        }, 
        clearList() { 
            this.list.clear(); 
        }, 
        contains(item) { 
            let res = this.list.includes(JSON.parse(item)); 
            alert(`The list ${res  
                ? '' : 'does not'} contains ${item}`); 
        }, 
        checkLastIndex(item) { 
            let res = this.list.lastIndexOf(JSON.parse(item)); 
            alert(res); 
        }, 
    }, 
});

应用程序/模板/lastIndexOf1.hbs


{{page-title "LastIndexOf"}} 
<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="contains-item"
        value="Contains?"
        {{action "contains" this.item2}} 
    /> 
</div> 
<br/> 
<div> 
    <input 
        type="button"
        id="check-item"
        value="Check Last Index"
        {{action "checkLastIndex" 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 "insertItem" this.item }} 
    /> 
</div> 
<br /> 
<input type="button" id="clear-items" 
    value="Clear"
    {{action "clearList"}} /> 
{{outlet}}

输出：访问 localhost:4200/lastIndexOf1 查看输出

Ember.js ArrayProxy的lastIndexOf方法

示例 2：键入以下代码以生成本示例的路由：

ember generate route lastIndexOf2

应用程序/路线/lastIndexOf2.js


import Route from '@ember/routing/route'; 
  
export default class PartyRoute extends Route { 
    partyItems = [ 
        'Oxygen', 
        'Source Code', 
        'Infine', 
        'Tenet', 
        'SpiderHead', 
        'The Thing', 
        'A Quiet Place', 
        'The Invisible Man', 
        'Looper', 
        'Ad Astra'
    ]; 
  temp = [ 
        '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('temp', this.temp); 
    } 
}

应用程序/控制器/lastIndexOf2.js


import Ember from 'ember'; 
import { pushObject, pushObjects, lastIndexOf, includes } 
    from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        insertItem(item) { 
            this.partyItems.pushObject(item); 
        }, 
        push_item(data) { 
            this.partyItems.pushObjects(data); 
        }, 
        contains(item) { 
            let res = this.partyItems.includes(item); 
            alert(`The List ${res  
                ? '' : 'does not'} contains ${item}`); 
        }, 
        checkLastindex(item) { 
            let res = this.partyItems.lastIndexOf(item); 
            alert(res); 
        }, 
    }, 
});

应用程序/模板/lastIndexOf2.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> 
    <input 
        type="button"
        id="insert-item"
        value="Insert Item"
        {{action "insertItem" this.item}} 
    /> 
</div> 
<br /> 
<div> 
    <label>Enter Item: </label> 
    {{input value=this.item2}} 
</div> 
<div> 
    <input 
        type="button"
        id="contains-item"
        value="Contains?"
        {{action "contains" this.item2}} 
    /> 
</div> 
<br/> 
<div> 
    <input 
        type="button"
        id="get-item"
        value="Get Last Index"
        {{action "checkLastindex" this.item2}} 
    /> 
</div> 
<br /> 
<input 
        type="button"
        id="contains-item"
        value="Add Movies"
        {{action "push_item" this.temp}} 
    /> 
{{outlet}}

输出：访问 localhost:4200/lastIndexOf2 查看输出

Ember.js ArrayProxy的lastIndexOf方法

参考：https://api.emberjs.com/ember/4.6/classes/ArrayProxy/methods/lastIndexOf?anchor=lastIndexOf

相关用法

注：本文由纯净天空筛选整理自satyam00so大神的英文原创作品 Ember.js ArrayProxy lastIndexOf() Method。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。