Ember.js EmberArray 的 find() 方法

Ember.js 是一种开源的 JavaScript 框架，用于开发基于模型-视图-控制器（MVC）架构的大型客户端 Web 应用程序。Ember.js 是最广泛使用的前端应用程序框架之一，旨在加快开发速度并提高生产力。目前，它被许多网站使用，包括Square，Discourse，Groupon，Linked In，Live Nation，Twitch 和 Chipotle。

find() 方法用于判断列表中是否存在某个项。

语法：

find(callback, target);

参数:

callback: 它是用来检查列表中项目的回调函数。
target: 它是要检查其元素的对象。

返回值: 找到的项目或’undefined’。

安装和运行Ember.js的步骤:

步骤1: 要运行以下示例，您需要拥有一个Ember项目。要创建一个项目，您需要首先安装ember-cli。在终端中输入以下代码：

npm install ember-cli

步骤2： 现在，您可以通过输入以下代码来创建项目：

ember new <project-name> --lang en

启动服务器的方式如下：

ember serve

示例1

输入以下代码以生成此示例的路由：

ember generate route find1

app/routes/find1.js

import Route from '@ember/routing/route'; 
  
export default class DetailsRoute extends Route { 
    details = [ 
        { 
            name: 'Aaksh', 
            mobile: '9811129967', 
            city: 'Delhi', 
            country: 'India', 
            gender: 'M', 
            zipCode: '800020', 
        }, 
        { 
            name: 'Sweta', 
            mobile: '9456712890', 
            city: 'Mumbai', 
            country: 'India', 
            gender: 'F', 
            zipCode: '400001', 
        }, 
        { 
            name: 'Satyam', 
            mobile: '2222222222', 
            city: 'Raipur', 
            country: 'India', 
            gender: 'M', 
            zipCode: '110012', 
        }, 
        { 
            name: 'Shandya', 
            mobile: '1122113322', 
            city: 'Bangalore', 
            country: 'India', 
            gender: 'F', 
            zipCode: '530068', 
        }, 
        { 
            name: 'Ayushi', 
            mobile: '2244668800', 
            city: 'Thana', 
            country: 'India', 
            gender: 'F', 
            zipCode: '302001', 
        }, 
    ]; 
    someMoreDetails = [ 
        { 
            name: 'Yogesh', 
            mobile: '1133557799', 
            city: 'Chennai', 
            country: 'India', 
            gender: 'F', 
            zipCode: '600001', 
        }, 
        { 
            name: 'Sunny', 
            mobile: '9911000000', 
            city: 'Masore', 
            country: 'India', 
            gender: 'M', 
            zipCode: '574142', 
        }, 
        { 
            name: 'Khushi', 
            mobile: '8888888888', 
            city: 'Pune', 
            country: 'India', 
            gender: 'F', 
            zipCode: '111045', 
        }, 
    ]; 
    city; 
    name; 
    code; 
    model() { 
        return this.details; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('details', this.details); 
        controller.set('someMoreDetails', this.someMoreDetails); 
        controller.set('city', this.city); 
        controller.set('code', this.code); 
        controller.set('name', this.name); 
    } 
}

app/controllers/find1.js

import Ember from 'ember'; 
import { addObjects, shiftObject, setEach } 
    from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        checkCity(city) { 
            alert(`Name Person from {city}:  
      {this.details.find((user) => 
                user.city == this.city).name}`); 
        }, 
        checkName(name) { 
            alert(`{name} Details:  
      {JSON.stringify(this.details. 
                find((user) 
                    => user.name == this.name))}`); 
        }, 
        checkCode(code) { 
            alert(`Name Person from zip-code  
        {code} is :  
       {this.details.find((user) => 
                user.zipCode == this.code).name}`); 
        }, 
    }, 
});

app/templates/find1.hbs

{ { 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 City: </label> 
    {{input value=this.city}} 
</div> 
<div> 
    <input 
        type="button"
        id="check-city"
        value="Check Someone from City"
        {{action "checkCity" this.city}} 
    /> 
</div> 
<br /><br /> 
<div> 
    <label>Enter zipCode: </label> 
    {{input value=this.code}} 
</div> 
<div> 
    <input 
        type="button"
        id="check-code"
        value="Check Someone from Zip-Code"
        {{action "checkCode" this.code}} 
    /> 
</div><br /><br /> 
<div> 
    <label>Enter Name: </label> 
    {{input value=this.name}} 
</div> 
<div> 
    <input 
        type="button"
        id="check-name"
        value="Check Someone by Name"
        {{action "checkName" this.name}} 
    /> 
</div> 
{ { outlet } }

输出: 访问localhost:4200/find1以查看输出

Ember.js EmberArray 的 find() 方法

示例2

键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'; 
import { } from '@ember/array'; 
  
export default class FruitsRoute  
extends Route { 
    item1 = [ 
        { 
            name: 'Apple', 
            isFruit: true, 
            color: 'red', 
        }, 
        { 
            name: 'Grapes', 
            isFruit: true, 
            color: 'green', 
        }, 
        { 
            name: 'Mango', 
            isFruit: true, 
            color: 'yellow', 
        }, 
        { 
            name: 'Watermelon', 
            isFruit: true, 
            color: 'red', 
        }, 
        { 
            name: 'Orange', 
            isFruit: true, 
            color: 'orange', 
        }, 
        { 
            name: 'Lady Finger', 
            isFruit: false, 
            color: 'green', 
        }, 
        { 
            name: 'Brinjal', 
            isFruit: false, 
            color: 'purple', 
        }, 
        { 
            name: 'Potato', 
            isFruit: false, 
            color: 'brown', 
        }, 
        { 
            name: 'Onion', 
            isFruit: false, 
            color: 'violet', 
        }, 
    ]; 
    model() { 
        return this.item1; 
    } 
    setupController(controller, model) { 
        super.setupController(controller, model); 
        controller.set('item1', this.item1); 
    } 
}

app/controllers/find2.js

import Ember from 'ember'; 
import { 
    removeAt, unshiftObjects, objectAt, 
    uniqBy, find 
} from '@ember/array'; 
  
export default Ember.Controller.extend({ 
    actions: { 
        removeDetails(start, end) { 
            this.item1.removeAt(start, end); 
        }, 
        getDetail(index) { 
            let foo = this.item1.objectAt(index); 
            alert(foo.name); 
        }, 
        getFirstFruit() { 
            let foo = this.item1.find( 
                (detail) => 
                    detail.isFruit === false); 
            alert(foo.name); 
        }, 
        getFirstVegy() { 
            let foo = this.item1.find( 
                (detail) => 
                    detail.isFruit === true); 
            alert(foo.name); 
        }, 
    }, 
});

app/templates/find2.hbs

{{page-title "Fruits"}} 
<table style=" border-spacing : 30px"> 
    <h3>Here is a list 1: </h3> 
    <ul> 
        {{#each @model as |eatable|}} 
            <li>{{eatable.name}}</li> 
        {{/each}} 
    </ul> 
</table> 
<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="all-male"
    value="Get First Fruit"
    {{action "getFirstFruit"}} 
/> 
<br /><br /> 
<input 
    type="button"
    id="get"
    value="Get First Vegetable"
    {{action "getFirstVegy"}} 
/> 
  
{{outlet}}