封装和抽象之间的确切区别是什么?
当前回答
抽象是广义的术语。即封装是抽象的子集。
| Abstraction | Encapsulation |
|---|---|
| It solves an issue at the design level. | Encapsulation solves an issue at implementation level. |
| hides the unnecessary detail but shows the essential information. | It hides the code and data into a single entity or unit so that the data can be protected from the outside world. |
| Focuses on the external lookout. | Focuses on internal working. |
| Lets focus on what an object does instead of how it does it. | Lets focus on how an object does something. |
| Example: Outer look of mobile, like it has a display screen and buttons. | Example: Inner details of mobile, how button and display screen connect with each other using circuits. |
示例:解决方案架构师是创建整个解决方案的高级抽象技术设计的人，然后将该设计移交给开发团队进行实现。 在这里，解决方案架构师充当抽象，而开发团队充当封装。
举例:用户数据的封装(组网)
图片由
Abstraction (or modularity) – Types enable programmers to think at a higher level than the bit or byte, not bothering with low-level implementation. For example, programmers can begin to think of a string as a set of character values instead of as a mere array of bytes. Higher still, types enable programmers to think about and express interfaces between two of any-sized subsystems. This enables more levels of localization so that the definitions required for interoperability of the subsystems remain consistent when those two subsystems communicate. Source
Java示例
其他回答
抽象是广义的术语。即封装是抽象的子集。
| Abstraction | Encapsulation |
|---|---|
| It solves an issue at the design level. | Encapsulation solves an issue at implementation level. |
| hides the unnecessary detail but shows the essential information. | It hides the code and data into a single entity or unit so that the data can be protected from the outside world. |
| Focuses on the external lookout. | Focuses on internal working. |
| Lets focus on what an object does instead of how it does it. | Lets focus on how an object does something. |
| Example: Outer look of mobile, like it has a display screen and buttons. | Example: Inner details of mobile, how button and display screen connect with each other using circuits. |
示例:解决方案架构师是创建整个解决方案的高级抽象技术设计的人，然后将该设计移交给开发团队进行实现。 在这里，解决方案架构师充当抽象，而开发团队充当封装。
举例:用户数据的封装(组网)
图片由
Abstraction (or modularity) – Types enable programmers to think at a higher level than the bit or byte, not bothering with low-level implementation. For example, programmers can begin to think of a string as a set of character values instead of as a mere array of bytes. Higher still, types enable programmers to think about and express interfaces between two of any-sized subsystems. This enables more levels of localization so that the definitions required for interoperability of the subsystems remain consistent when those two subsystems communicate. Source
Java示例
有一件事，也许是其他答案忘记提到的一个基本的事情是，封装是抽象。因此，将两者进行对比并寻找差异是不准确的，而应该将封装视为一种抽象形式。
让我们以堆栈为例。它可以使用数组或链表来实现。但它支持的操作是推送和弹出。
Now abstraction is exposing only the interfaces push and pop. The underlying representation is hidden (is it an array or a linked list?) and a well-defined interface is provided. Now how do you ensure that no accidental access is made to the abstracted data? That is where encapsulation comes in. For example, classes in C++ use the access specifiers which ensure that accidental access and modification is prevented. And also, by making the above-mentioned interfaces as public, it ensures that the only way to manipulate the stack is through the well-defined interface. In the process, it has coupled the data and the code that can manipulate it (let's not get the friend functions involved here). That is, the code and data are bonded together or tied or encapsulated.
抽象:只显示必要的信息。让我们关注一下在计算机上进行开关的例子。当系统仍在加载时，用户不必知道发生了什么(该信息对用户隐藏)。
让我们再举一个例子，ATM机。客户不需要知道机器如何读取密码并处理交易，他所需要做的就是输入密码，拿现金然后离开。
封装:处理隐藏类的敏感数据，从而私有化类的一部分。这是一种通过不允许外部访问来保持某些信息对其客户端的私密性的方法。
封装隐藏了实现细节，这些细节可能是通用的，也可能不是专门的行为。
抽象提供了一种泛化(例如，在一组行为之上)。
这里有一个很好的阅读:抽象、封装和信息隐藏，作者是Object Agency的Edward V. Berard。
