封装和抽象之间的确切区别是什么?
当前回答
抽象和封装都是用来隐藏数据的。但是有很大的不同。
封装
封装是将数据和对数据进行操作的代码绑定或包装成一个称为Class的单元的过程。
封装在实现级别解决了问题。
在类中，可以使用私有或受保护的访问修饰符来隐藏数据。
抽象
抽象是隐藏无关细节的概念。换句话说，通过对用户隐藏不必要的细节，使复杂的系统变得简单。
抽象在设计层面解决了问题。
可以通过在Java中创建接口和抽象类来实现抽象。
在ruby中，你可以通过创建模块来实现抽象。
示例:我们使用(收集，映射，减少，排序…)方法的枚举模块与数组和ruby哈希。
其他回答
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
抽象是对用户隐藏无用的数据 封装是将数据绑定到一个胶囊(类)中。 我认为封装是我们实现抽象的方式。
抽象—隐藏实现—在设计—使用接口/抽象类
封装—隐藏数据—在开发时—使用访问修饰符(公共/私有)
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。
