Embeer.js Ember.NativeArray 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() 方法用于查找数组中最后一次出现的传递对象的索引。

用法:

lastIndexOf( object, startAt );

参数：

object: 它是我们想要出现的对象。
startAt: 它是从哪里开始查找的索引号。

返回值：数组中对象的最后一个索引；如果未找到，则返回 -1。

第 1 步：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

第 2 步：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

Javascript


import Route from "@ember/routing/route"; 
  
export default class StudentsRoute extends Route { 
    partyItems = [ 
        'Digital Camera', 
        'Jugs, cups & straws', 
        'Balloons', 
        'Cups', 
        'Scissors', 
        'Cold Drink', 
        'Table Confetti', 
        'Party Hats', 
        'Wine', 
        'Napkins', 
        'Scissors', 
        'Party Plates', 
        'Speakers', 
        'Music System', 
        'Cold Drink', 
        'Cups', 
        'Wine', 
    ]; 
    len; 
    model() { 
        return this.partyItems; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set("partyItems", this.partyItems); 
        controller.set("len", this.len); 
        controller.set("item", this.item); 
    } 
}

应用程序/控制器/lastIndexOf1.js

Javascript


import Ember from "ember"; 
  
export default Ember.Controller.extend({ 
    actions: { 
        last_index(data) { 
            let ans = this.partyItems.lastIndexOf(data); 
            alert(`Last Index of item is ${ans}`); 
        }, 
        check_items(data) { 
            let temp = this.partyItems.includes(data) 
            alert(temp ? "Item is present in list" :  
                "Item is not Present in list") 
        }, 
        find_index(data) { 
            let temp = this.partyItems.indexOf(data); 
            alert(`Index of ${data} is ${temp}`) 
        }, 
  
    }, 
});

应用程序/模板/lastIndexOf1.hbs

Javascript


{{page-title "lastIndexOf"}} 
<h3>List of Items: </h3> 
<table> 
    <ul> 
        {{#each @model as |student|}} 
            <li>{{student}}</li> 
        {{/each}} 
      </ul> 
</table> 
<br /><br /> 
<div> 
    <label>Enter Item: </label> 
      {{input value=this.temp}} 
</div> 
<input 
    type="button"
      id="check-atIndex"
      value="Check Item"
      {{action "check_items" this.temp}} 
/> 
<br /><br /> 
<div> 
    <label>Enter Item: </label> 
      {{input value=this.temp1}} 
</div> 
<input 
    type="button"
      id="find-Index"
      value="Find Index Of Item"
      {{action "find_index" this.temp1}} 
/> 
<br /><br /> 
<div> 
    <label>Enter Item: </label> 
      {{input value=this.temp2}} 
</div> 
<input 
    type="button"
      id="find-last"
      value="Find last Index"
      {{action "last_index" this.temp2}} 
/> 
{{outlet}}

输出：访问 localhost:4200/lastIndexOf1 查看输出。

Ember.js Ember.NativeArray 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

Javascript


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

应用程序/控制器/lastIndexOf2.js

Javascript


import Ember from 'ember'; 
import { } from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        check_index(item) { 
            let temp = this.partyItems.indexOf(item); 
            alert(`Index of Movie is ${temp}`); 
        }, 
        check_movie(item) { 
            let temp = this.partyItems.includes(item); 
            alert(temp ? 'Movie is present in watch list' :  
                'Movie is not Present in watch list'); 
        }, 
        check_last(item) { 
            let temp = this.partyItems.lastIndexOf(item); 
            alert(`Last Index of Movie is ${temp}`); 
        }, 
    }, 
});

应用程序/模板/lastIndexOf2.hbs

Javascript


{{page-title "lastIndexOf"}} 
<h3>Here is a list of items: </h3> 
<ul> 
    {{#each @model as |party|}} 
        <li>{{party}}</li> 
    {{/each}} 
</ul> 
<br /><br /> 
<div> 
    <label>Enter Movie: </label> 
    {{input value=this.temp}} 
</div> 
<input 
    type="button"
    id="find-Index"
    value="Find Movie Index"
    {{action "check_index" this.temp}} 
/> 
<br /><br /> 
<div> 
    <label>Enter Movie: </label> 
    {{input value=this.temp1}} 
</div> 
<input 
    type="button"
    id="check-movie"
    value="Check Movie"
    {{action "check_movie" this.temp1}} 
/> 
<br /><br /> 
<div> 
    <label>Enter Item: </label> 
    {{input value=this.temp2}} 
</div> 
<input 
    type="button"
    id="check-last"
    value="Check Last Index of Movie"
    {{action "check_last" this.temp2}} 
/> 
{{outlet}}

输出：访问 localhost:4200/lastIndexOf2 查看输出

Ember.js Ember.NativeArray lastIndexOf 方法

参考：https://api.emberjs.com/ember/4.4/classes/Ember.NativeArray/methods/lastIndexOf?anchor=lastIndexOf

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注：本文由纯净天空筛选整理自jeemains0neet大神的英文原创作品 Ember.js Ember.NativeArray 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。