什麼是抽象

什麼是抽象

1. 抽象VS封裝

Abstraction is the concept of describing something in simpler terms, i.e abstracting away the details, in order to focus on what is important (This is also seen in abstract art, for example, where the artist focuses on the building blocks of images, such as colour or shapes). The same idea translates to OOP by using an inheritance hierarchy, where more abstract concepts are at the top and more concrete ideas, at the bottom, build upon their abstractions. At its most abstract level there is no implementation details at all and perhaps very few commonalities, which are added as the abstraction decreases.

As an example, at the top might be an interface with a single method, then the next level, provides several abstract classes, which may or may not fill in some of the details about the top level, but branches by adding their own abstract methods, then for each of these abstract classes are concrete classes providing implementations of all the remaining methods.

Encapsulation is a technique. It may or may not be for aiding in abstraction, but it is certainly about information hiding and/or organisation. It demands data and functions be grouped in some way - of course good OOP practice demands that they should be grouped by abstraction. However, there are other uses which just aid in maintainability etc.

來自於 https://stackoverflow.com/questions/8960918/encapsulation-vs-abstraction