Embeer.js Ember.NativeArray removeAt()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。

removeAt() 方法用于删除给定索引上的元素。

用法:

removeAt(start, len)

参数：

start：起始索引。
len：要删除的元素的长度。

返回值：没有什么

安装和运行 Ember.js 的步骤：

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 party

应用程序/路线/party.js

Javascript


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

应用程序/控制器/party.js

Javascript


import Ember from "ember"; 
import { 
    without, 
    toArray, 
    unshiftObject, 
    unshiftObjects, 
    removeAt, 
    objectAt, 
    find, 
    replace, 
    uniq, 
} from "@ember/array"; 
  
export default Ember.Controller.extend({ 
    actions: { 
        withoutItem(item) { 
            console.log(item); 
            let tempItems; 
            tempItems = this.partyItems.without(item); 
            let str = ""; 
            for (let i = 0; i < tempItems.length; i++) 
                str += tempItems[i] + "\n"; 
            alert(str); 
            this.set("item", ""); 
        }, 
        addItems(itemString) { 
            this.itemList = itemString.split(",").toArray(); 
            if (this.itemList.length == 1) 
                this.partyItems.unshiftObject(this.itemList[0]); 
            else this.partyItems.unshiftObjects(this.itemList); 
            this.set("itemString", ""); 
        }, 
        removeItems(start, end) { 
            this.partyItems.removeAt(start, end); 
        }, 
        getObject(idx) { 
            alert( 
                `The item at index ${idx} is  
                  ${this.partyItems.objectAt(idx)}` 
            ); 
        }, 
        findMultipleWordItems() { 
            let reqItem = this.partyItems.find( 
                (item) => item.split(" ").toArray().length > 1 
            ); 
            alert(reqItem); 
        }, 
        replaceItem(itemString) { 
            this.itemList = itemString.split(",").toArray(); 
            if (this.itemList.length >  
                this.partyItems.length) alert("Error"); 
            this.partyItems.replace(0,  
                this.itemList.length, this.itemList); 
        }, 
        getUniqueItems() { 
            let tempItems = this.partyItems.uniq(); 
            let str = ""; 
            for (let i = 0; i < tempItems.length; i++) 
                str += tempItems[i] + "\n"; 
            alert(str); 
            this.set("item", ""); 
        }, 
    }, 
});

应用程序/模板/party.hbs

HTML


{{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="remove-item"
        value="Remove Item"
        {{action "withoutItem" this.item}} 
    /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Items: </label> 
    {{input value=this.itemString}} 
</div> 
<div> 
    <input
        type="button"
        id="add-item"
        value="Add Items"
        {{action "addItems" this.itemString}} 
    /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Start Index: </label> 
    {{input value=this.start}} 
</div> 
<div> 
    <label>Enter End Index: </label> 
    {{input value=this.end}} 
</div> 
<div> 
    <input
        type="button"
        id="remove-items"
        value="Remove Items"
        {{action "removeItems" this.start this.end}} 
    /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Index: </label> 
    {{input value=this.idx}} 
</div> 
<div> 
    <input
        type="button"
        id="get-item"
        value="Get Item"
        {{action "getObject" this.idx}} 
    /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Items: </label> 
    {{input value=this.itemString}} 
</div> 
<div> 
    <input
        type="button"
        id="replace-item"
        value="Replace Items"
        {{action "replaceItem" this.itemString}} 
    /> 
</div> 
<br /><br /> 
<input
    type="button"
    id="get-multiword"
    value="Get Multiword Items!"
    {{action "findMultipleWordItems"}} 
/> 
<br /><br /> 
<input
    type="button"
    id="get-unique"
    value="Get Unique Items!"
    {{action "getUniqueItems"}} 
/> 
  
{{outlet}}

输出：访问 localhost:4200/party 查看输出

示例 2：键入以下代码以生成本示例的路由：

ember generate route details

应用程序/路线/details.js

Javascript


import Route from '@ember/routing/route'; 
  
export default class DetailsRoute extends Route { 
  details = [ 
    { 
      name: 'Anubhav', 
      mobile: '1298119967', 
      city: 'Patna', 
      country: 'India', 
      gender: 'M', 
      zipCode: '800020', 
    }, 
    { 
      name: 'Sakshi', 
      mobile: '1234567890', 
      city: 'Mumbai', 
      country: 'India', 
      gender: 'F', 
      zipCode: '400001', 
    }, 
    { 
      name: 'Satyam', 
      mobile: '2222222222', 
      city: 'Delhi', 
      country: 'India', 
      gender: 'M', 
      zipCode: '110012', 
    }, 
    { 
      name: 'Shivam', 
      mobile: '1122113322', 
      city: 'Bangalore', 
      country: 'India', 
      gender: 'M', 
      zipCode: '530068', 
    }, 
    { 
      name: 'Ayushi', 
      mobile: '2244668800', 
      city: 'Jaipur', 
      country: 'India', 
      gender: 'F', 
      zipCode: '302001', 
    }, 
  ]; 
  someMoreDetails = [ 
    { 
      name: 'Yeshwant', 
      mobile: '1133557799', 
      city: 'Chennai', 
      country: 'India', 
      gender: 'M', 
      zipCode: '600001', 
    }, 
    { 
      name: 'Siddhant', 
      mobile: '9911000000', 
      city: 'Mangalore', 
      country: 'India', 
      gender: 'M', 
      zipCode: '574142', 
    }, 
    { 
      name: 'Khushi', 
      mobile: '8888888888', 
      city: 'Pune', 
      country: 'India', 
      gender: 'F', 
      zipCode: '111045', 
    }, 
  ]; 
  start; 
  end; 
  idx; 
  model() { 
    return this.details; 
  } 
  setupController(controller, model) { 
    super.setupController(controller, model); 
    controller.set('details', this.details); 
    controller.set('someMoreDetails', this.someMoreDetails); 
    controller.set('start', this.start); 
    controller.set('end', this.end); 
    controller.set('idx', this.idx); 
  } 
}

应用程序/控制器/details.js

Javascript


import Ember from 'ember'; 
import { removeAt, unshiftObjects, objectAt, uniqBy, find } 
    from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        removeDetails(start, end) { 
            this.details.removeAt(start, end); 
        }, 
        addMoreDetails() { 
            this.details.unshiftObjects(this.someMoreDetails); 
        }, 
        getDetail(index) { 
            let foo = this.details.objectAt(index); 
            alert(foo.name); 
        }, 
        getFirstMaleAndFemalePerson() { 
            let foo = this.details.uniqBy('gender').toArray(); 
            let str = ""; 
            for (let i = 0; i < foo.length; i++) 
                str += foo[i].name + "\n"; 
            alert(str); 
        }, 
        getFirstMale() { 
            let foo = this.details.find( 
                (detail) => detail.gender === 'M'); 
            alert(foo.name); 
        }, 
    }, 
});

应用程序/模板/details.hbs

HTML


{{page-title "Details"}} 
<h3>List of People: </h3> 
<br /><br /> 
<table> 
    <tr> 
        <th>Name</th> 
        <th>Gender</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.mobile}}</td> 
            <td>{{detail.city}}</td> 
            <td>{{detail.country}}</td> 
            <td>{{detail.zipCode}}</td> 
        </tr> 
    {{/each}} 
</table> 
<br /><br /> 
<div> 
    <label>Enter Start Index: </label> 
    {{input value=this.start}} 
</div> 
<div> 
    <label>Enter End Index: </label> 
    {{input value=this.end}} 
</div> 
<div> 
    <input
        type="button"
        id="remove-details"
        value="Remove Details"
        {{action "removeDetails" this.start this.end}} 
    /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter Index: </label> 
    {{input value=this.idx}} 
</div> 
<div> 
    <input
        type="button"
        id="get-detail"
        value="Get detail"
        {{action "getDetail" this.idx}} 
    /> 
</div> 
<br /><br /> 
<input
    type="button"
    id="add-details"
    value="Add More Details"
    {{action "addMoreDetails"}} 
/> 
<br /><br /> 
<input
    type="button"
    id="all-male"
    value="Get First Male"
    {{action "getFirstMale"}} 
/> 
<br /><br /> 
<input
    type="button"
    id="get"
    value="Get"
    {{action "getFirstMaleAndFemalePerson"}} 
/> 
{{outlet}}

输出：访问 localhost:4200/details 查看输出

参考：https://api.emberjs.com/ember/4.6/classes/Ember.NativeArray/methods

相关用法

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