blocks|key|604586|text|它试图模拟OOP范例，仅此而已。有多种方法可以做到这一点。但是问问你自己，'hi‘是属于'obj’，还是可以是一个独立的函数？这一切都取决于函数与对象的关系有多密切。函数是否需要访问对象、私有变量等？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|604587|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

It tries to simulate the OOP paradigm that's all. There are various ways of doing this. But ask yourself, doe 'hi' belong in 'obj' or can it be a standalone function? Its all about how closely related is the function to the object. Does the function needs to access the objects private variables and such?

blocks|key|604625|text|如果没有你所说的对象，你将会到处都是松散的函数。这通常会导致代码很难维护。最低限度，对象使您能够将函数集中在一起以模拟名称空间--这是最低限度的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|604626|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Without what you are referring to as objects, you are going to have loose functions all over the place. This very often will result in code that is very difficult to maintain. At a bare minimum objects give you the ability to lump functions together in order to simulate namespaces-- and that's at a bare minimum.

blocks|key|604682|text|在您的简单示例中，编写一个半“类”/对象来保存该方法确实没有任何意义。但是当您的代码增长时，您将获得越来越多的函数和方法，您不会真的希望将它们都放在一个大的(全局)名称空间中。这实在是太难维护了，在以后的某个时刻，包括你在内，没有人会理解这些代码。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|604683|这是将方法包装在一个对象/“类”中的第一个好理由。另一个很好的原因是可重用性。如果您正在编写能够继承其方法的对象，则可以重新创建另一个对象并从那里对其进行抽象。最简单的概念，但是如果你想在你的应用程序中把“事物”描述为模块/对象，你就需要使用它。|604684|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

In your simple example, it makes indeed no sense to write a semi "class" / object to hold that method. But when your code grows, you're getting more and more functions and methods, you don't really want to have them all in one big (global) namespace. That is just so impossible to maintenain, no one will understand that code including you at some later point.

That is the first good reason to wrap methods together in an object/"class". Another good reason is re-usabilty. If you're writting objects which are able to inherit their methods, you can re-create another object and abstract it from there on. Most simple concept, but you want to use it if you're describing "things" in your application as module/object.

blocks|key|819856|text|对象很有用，例如，将属于一起的值组成一个单元。示例：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|819857|function+Person(firstName,+lastName,+gender,+age)+{
++this.firstName+=+firstName;
++this.lastName+=+lastName;
++this.gender+=+gender;
++this.age+=+age;
}

Person.prototype+=+{
++getFullName:+function()+{+return+this.firstName+%2B+'+'+%2B+this.lastName;+},
++isMale:+function()+{+return+this.gender+==+'Male';+},
++isFemale:+function()+{+return+this.gender+==+'Female';+}
};

var+amanda+=+new+Person('Amanda',+'Smith',+"Female",+42);
var+john+=+new+Person('John',+'Doe',+'Male',+72);

alert(amanda.getFullName());
alert(john.isMale());|code-block|syntax|javascript|819858|与结构较差的相比：|819859|function+getFullName(firstName,+lastName)+{
++return+firstName+%2B+'+'+%2B+lastName;
}

function+isMale(gender)+{
++return+gender+==+'Male';
}

function+isFemale(gender)+{
++return+gender+==+'Female';
}

var+amandaFirstName+=+'Amanda';
var+amandaLastName+=+'Smith';
var+amandaGender+=+'Female';
var+amandaAge+=+42;
var+johnFirstName+=+'John';
var+johnLastName+=+'Doe';
var+johnGender+=+'Male';
var+johnAge+=+72;

alert(getFullName(amandaFirstName,+amandaLastName));
alert(isMale(johnGender));|819860|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Objects are useful for example for making a single unit out of values that belong together. Example:

<pre><code>function Person(firstName, lastName, gender, age) {
 this.firstName = firstName;
 this.lastName = lastName;
 this.gender = gender;
 this.age = age;
}

Person.prototype = {
 getFullName: function() { return this.firstName + ' ' + this.lastName; },
 isMale: function() { return this.gender == 'Male'; },
 isFemale: function() { return this.gender == 'Female'; }
};

var amanda = new Person('Amanda', 'Smith', "Female", 42);
var john = new Person('John', 'Doe', 'Male', 72);

alert(amanda.getFullName());
alert(john.isMale());
</code></pre>

Compared to the less structured:

<pre><code>function getFullName(firstName, lastName) {
 return firstName + ' ' + lastName;
}

function isMale(gender) {
 return gender == 'Male';
}

function isFemale(gender) {
 return gender == 'Female';
}

var amandaFirstName = 'Amanda';
var amandaLastName = 'Smith';
var amandaGender = 'Female';
var amandaAge = 42;
var johnFirstName = 'John';
var johnLastName = 'Doe';
var johnGender = 'Male';
var johnAge = 72;

alert(getFullName(amandaFirstName, amandaLastName));
alert(isMale(johnGender));
</code></pre>

blocks|key|604758|text|关于“为什么”部分的一些一般性思考：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|604759|对象的存在是为了通信。它是参与项目的每个人的通用词汇表。人们习惯于操作事物(对象)及其操作(消息或方法)，而不仅仅是操作断开的操作(函数)。|604760|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

Some generic thoughts concerning "Why" part:

Objects exist to communicate. It is a common vocabulary for everyone involved in a project. People are used to operate with things (objects) and their operations (messages or methods), rather than just with disconnected actions (functions).

I understand how to instantiate objects and call them, but I just cannot find a reason to use them in my script. I could do 

<pre><code>var obj = {
 hi: function() {
 return "Hello";
 }
}; 
</code></pre>

but why can't I just do it the same way like:

<pre><code>function hi() {
 return "Hello";
}
</code></pre>

I've never understood the reasons why I should use prototyping either. Most of the things I do in JavaScript I can do well without objects. But I want to use objects. What are objects for and what are the reasons why I should use them?

Why/How should I used objects in JavaScript?

我知道如何实例化对象并调用它们，但我就是找不到在我的脚本中使用它们的理由。我能做到var obj = {    hi: function() {        return "Hello";    }}; 但是为什么我不能像这样做：function hi() {    return "Hello";}我也从来没有理解过...

问为什么/如何在JavaScript中使用对象？
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