Understand ADT and OOP

Catalog

ADT

1. Concept

2. form

3. significance

OOP

1. Concept

2. The core concept

ADT And OOP The relationship between

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ADT

1. Concept

A mathematical model and a set of operations defined on it , The definition of an abstract data type depends on only one set of its logical characteristics , It has nothing to do with how it is represented and implemented inside the computer

2. form

An abstract data type defines ： A data object 、 The relationship between the data elements in the data object and the operation on the data elements

3. significance

Abstract data types embody problem decomposition in programming 、 The characteristics of abstraction and information hiding . Abstract data types decompose real-life problems into many small-scale and easy to deal with problems , Then build a data model that can be processed by computer , And the implementation details of each functional module as an independent unit , So that the specific implementation process can be hidden

OOP

1. Concept

Object oriented programming methods / Languages should have the concept of classes as the central concept . A language should be able to provide assertions for a class and its characteristics （ Namely specification ： precondition , Post conditions and invariants ） And exception handling , Rely on tools to generate documents in these assertions , And optionally monitor them at run time Time .

2. The core concept

① Static type ： A well-defined type system should ensure the runtime type safety of the system it accepts by enforcing some type declarations and compatibility rules .

② Generic （Genericity）： be used for “ Prepare for change ” and “ by / Reuse design ”： It should be possible to write classes with formal generic parameters that represent any type .

③ Inherit （Inheritance）： It should be possible to define a class as inheriting from another , To control the potential complexity .

④ polymorphic （Polymorphism）： Under the control of an inheritance based type system , It should be possible to （ The name in the software text that represents the runtime object ） Attach to various possible types of runtime objects .

⑤ Dynamic dispatch / binding （Dynamic dispatch / binding）： Calling a feature on an entity should always trigger the feature corresponding to the type of the attached runtime object , This is not necessarily the same in the different execution of the call .

ADT And OOP The relationship between

Four ideas of object-oriented programming ： encapsulation 、 Inherit 、 polymorphic 、 abstract
ADT It just reflects the two programming ideas of encapsulation and abstraction . Want to achieve ADT It has nothing to do with the implementation language （ No matter what language you use, you can embody a certain programming idea ）. So in your question “ Realize the encapsulation in object-oriented programming ” This statement has its own problems , Can't say “ Realization ” A certain idea , It can only be said “ reflect ”.

Besides ,ADT（ Abstract data types ） Just a data type , This data type is a mathematical model and a set of operations defined on it . encapsulation 、 Inherit 、 polymorphic 、 Abstraction is the idea used in object-oriented programming ,ADT Not a language at all , It's just a model , The two can not be compared