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。

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。

抽象或封装并不严格要求信息隐藏。信息可能会被忽略，但不一定要隐藏。

封装是一种将事物视为单一事物的能力，即使它可能由许多复杂的部分或思想组成。例如，我可以说我坐在一把“椅子”上，而不是指这把椅子上的许多不同部分，每个部分都有特定的设计和功能，它们精确地组合在一起，目的是让我的屁股舒适地离地板几英尺远。

Abstraction is enabled by encapsulation. Because we encapsulate objects, we can think about them as things which relate to each other in some way rather than getting bogged down in the subtle details of internal object structure. Abstraction is the ability to consider the bigger picture, removed from concern over little details. The root of the word is abstract as in the summary that appears at the top of a scholarly paper, not abstract as in a class which can only be instantiated as a derived subclass.

I can honestly say that when I plop my butt down in my chair, I never think about how the structure of that chair will catch and hold my weight. It's a decent enough chair that I don't have to worry about those details. So I can turn my attention toward my computer. And again, I don't think about the component parts of my computer. I'm just looking at a part of a webpage that represents a text area that I can type in, and I'm communicating in words, barely even thinking about how my fingers always find the right letters so quickly on the keyboard, and how the connection is ultimately made between tapping these keys and posting to this forum. This is the great power of abstraction. Because the lower levels of the system can be trusted to work with consistency and precision, we have attention to spare for greater work.

另一个例子:

假设我创建了一个不可变的Rectangle类，如下所示:

class Rectangle {
 public:
  Rectangle(int width, int height) : width_(width), height_(height) {}
  int width() const { return width_; }
  int height() const { return height_; }

 private:
  int width_;
  int height_;
}

现在很明显，我已经封装了宽度和高度(访问受到某种限制)，但我没有抽象任何东西(好吧，也许我忽略了矩形在坐标空间中的位置，但这是示例的缺陷)。

好的抽象通常意味着好的封装。

一个好的抽象例子是通用数据库连接类。它的公共接口与数据库无关，非常简单，但允许我对连接做我想做的事情。你看到了吗?这里还有封装，因为类内部必须有所有低级句柄和调用。

简而言之

抽象使用->封装 ＆ 封装使用->数据隐藏

OR

数据隐藏是封装和的子集 封装是抽象的一个子集

参考:http://www.tonymarston.co.uk/php-mysql/abstraction.txt

从这个

OOPS中封装和抽象的区别

抽象和封装是两个重要的面向对象编程(oop)概念。封装和抽象都是相互关联的术语。

封装和抽象的现实区别

封装意味着隐藏。封装也称为数据隐藏。你可以把胶囊想象成胶囊(药片)，里面藏着药。封装是包装，只是隐藏属性和方法。封装用于将代码和数据隐藏在单个单元中，以保护数据不受外界的影响。类是封装的最佳示例。

抽象指的是只向预期的用户显示必要的细节。顾名思义，抽象是“任何事物的抽象形式”。我们在编程语言中使用抽象来创建抽象类。抽象类表示类的方法和属性的抽象视图。

封装和抽象之间的实现差异

Abstraction is implemented using interface and abstract class while Encapsulation is implemented using private and protected access modifier. OOPS makes use of encapsulation to enforce the integrity of a type (i.e. to make sure data is used in an appropriate manner) by preventing programmers from accessing data in a non-intended manner. Through encapsulation, only a predetermined group of functions can access the data. The collective term for datatypes and operations (methods) bundled together with access restrictions (public/private, etc.) is a class.