object-oriented language

Halcon学习笔记1、Halcon的自我描述Program LogicEach program consists of a sequence of HALCON operatorsThe program can be structured into proceduresThe sequence can be extended by using control operators like if, for, repeat, or whileThe results of the operators are passed via variablesNo implicit data passing is appliedInput parameters of operators can be variables or expressionsOutput parameters are always variablesHDevelop has no features to design a graphical user interfaceAn HDevelop program is considered as a prototypic solution of the vision part of an applicationHDevelop is typically not used for the final application由此可以看出，Halcon的定位是一个类库，有着完整、快速实现函数，同时提供了HDevelop 作为快速开发的图形化（IDE）界面；但是，Halcon程序并不是一个完整的最终应用软件，它没有用户界面，也不提供显示的数据（公用的数据格式）。

Halcon的初学者也应当从参考Halcon的程序入手，熟悉Halcon类库，也即HDevelop-Based Programming；在此基础上，进入ORClass-Oriented Programming。

⾯试官：什么是⾯向对象？⾯向对象是⼀种思想，世间万物都可以看做⼀个对象，这⾥只讨论⾯向对象编程。

（OOP-->Object Oriented Programming）Java 是⼀个⽀持并发、基于类和⾯向对象的计算机编程语⾔。

⾯向对象软件开发具有以下优点：代码开发模块化，更易维护和修改。

代码复⽤性强。

增强代码的可靠性和灵活性。

增加代码的可读性。

请说说⾯向对象的特征？四点：封装、继承、多态、抽象。

1）封装封装，给对象提供了隐藏内部特性和⾏为的能⼒。

对象提供⼀些能被其他对象访问的⽅法来改变它内部的数据。

在 Java 当中，有 4 种修饰符：default、public、private 和 protected 。

注意：java的访问控制是停留在编译层的，也就是它不会在.class⽂件中留下任何的痕迹，只在编译的时候进⾏访问控制的检查。

其实，通过反射的⼿段，是可以访问任何包下任何类中的成员，例如，访问类的私有成员也是可能的。

区别：public：可以被所有其他类所访问private：只能被⾃⼰访问和修改protected：⾃⾝、⼦类及同⼀个包中类可以访问default：同⼀包中的类可以访问，声明时没有加修饰符，认为是friendly。

每⼀种修饰符给其他的位于同⼀个包或者不同包下⾯对象赋予了不同的访问权限。

下⾯列出了使⽤封装的⼀些好处：通过隐藏对象的属性来保护对象内部的状态。

提⾼了代码的可⽤性和可维护性，因为对象的⾏为可以被单独的改变或者是扩展。

禁⽌对象之间的不良交互提⾼模块化。

2）继承继承，给对象提供了从基类获取字段和⽅法的能⼒。

继承提供了代码的重⽤⾏，也可以在不修改类的情况下给现存的类添加新特性。

3）多态多态，是编程语⾔给不同的底层数据类型做相同的接⼝展⽰的⼀种能⼒。

⼀个多态类型上的操作，可以应⽤到其他类型的值上⾯。

4）抽象抽象，是把想法从具体的实例中分离出来的步骤，因此，要根据他们的功能⽽不是实现细节来创建类。

信息英语词汇(O)信息英语词汇(O)信息英语词汇(O)o analysis mi 中档计算机object 目标object code 目标代码object command 目标命令object computer 目标计算机object file 目标文件object function 目标函数object instruction 目标指令object language 目标语言object library 目标库object listing 目标程序列表object machine 目标机object module 目标模块object module library 目标模块库object oriented architecture 面向目标的结构object oriented language 面向对象语言object oriented programming 面向目标程序设计object phase 目标阶段object program 目标程序object routine 目标程序objective function 目标函数observation error 观测误差occurrence 具体值ocr 光符识别ocr reader 光学符号阅读器ocra font ocr a型字符octal digit 八进制数字符octal notation 八进制记数法octal number 八进制数octal system 八进制记数法octant 八分圆octave analyzer 倍频程分析器octet 八位字节octtree 八进树odd check 奇数校验odd even check 奇偶校验odd function 奇函数odd harmonic 奇次谐波odd parity 奇数奇偶性odd parity check 奇数奇偶性较验oddness 奇数性oem 初始设备厂家oem hardware oem硬件off 断开off bit 零值位off hook 离钩off line 脱机的off line control 脱机控制off line data processing 脱机数据处理off line diagnosis 脱机诊断off line equipment 脱机设备off line mode 脱机方式off line operation 脱机操作off line output 脱机输出off line plotter 脱机绘图机off line processing 脱机处理off line storage 脱机存储器off line system 脱机系统off position 断路位置off screen memory 屏幕外存储器off the shelf software 现用软件off time 关机时间office 电话交换office automation 办公自动化office computer 办公用计算机office network 办公室网络offset 偏移offset address 偏移。

Aaddress bus 地址总线analog transmission 模拟传输analogue computer模拟计算机application program应用程序artificial intelligence 人工智能artificial language 人工语言assembly language 汇编语言assignment statement赋值语句atomic operation 原子操作Attachments line附件行audio signal 音频信号autonomous system 自主系统Bbcc line 密送行binary notation 二进制记数法BIOS (Basic Input/Output System)基本输入/输出系统broadband Internet access宽带因特网访问bus topology network 总线拓扑网络Ccarrier sense 载波检测，载波监听cathode ray tube 阴极射线管cc line 抄送行cell phone 蜂窝电话，移动电话，手机cellular telephone蜂窝电话，移动电话，手机central processing unit中央处理器classified information 密级信息click on an icon 点击图标client/server model客户机/服务器模型closed network封闭式网络commercial off-the-shelf software商用现成软件commonly used emoticon常用情感符communication(s) satellite通信卫星compiled language 编译执行的语言component-based software engineering 基于组件的软件工程computer programmer计算机程序员computer terminal 计算机终端conditional statement条件语句confidential document 密件，秘密文件copyright law版权法cordless telephone无绳电话cyber café网吧Ddata attribute数据属性data bus数据总线data declaration 数据声明data insertion and deletion数据插入与删除data type数据类型database administrator 数据库管理员database architecture数据库体系结构database management system (DBMS)数据库管理系统database object数据库对象debugging program调试程序decentralized network 分散型网络dedicated Internet connection专用因特网连接deleted e-mail已删除电子邮件device driver设备驱动程序dial-up connection 拨号连接difference engine 差分机digital computer数字计算机digital television 数字电视disk drive磁盘驱动器distributed database 分布式数据库dot-matrix printer点阵打印机（针式打印机）dotted decimal notation点分十进制记数法DSL 数字用户线路Eelectronic system电子系统e-mail convention 电子邮件常规e-mail netiquette电子邮件网规end user 最终用户，终端用户entity-relationship model (ERM)实体关系模型Ethernet protocol collection以太网协议集evolutionary development process演化开发过程executable program可执行程序exploratory programming approach探索式编程方法Ffax machine传真机fiber-optic cable光缆file server 文件服务器flat file 平面文件flatbed scanner 平板扫描仪forwarded e-mail messages转发的电子邮件function key 功能键，操作键function statement 函数语句functional language函数式语言Ggeneral-purpose computer通用计算机global control bus全局控制总线Hhardware and software support硬件与软件支持hierarchical database model层次数据库模型host address主机地址Iinference engine 推理机information superhighway信息高速公路ink cartridge墨盒inkjet printer喷墨打印机input device输入设备instruction set 指令集inter-machine cooperation机器间合作，计算机间合作intermediate language中间语言，中级语言intermediate program中间程序，过渡程序Internet addressing因特网编址Internet infrastructure 因特网基础结构Internet service provider (ISP)因特网服务提供商Internet-wide directory system因特网范围的目录系统interpreted language解释执行的语言interpreter program 解释程序interprocess communication进程间通信IP address 网际协议地址，IP地址laser printer激光打印机LCD (liquid crystal display)液晶显示（器）library routine 库程序，程序库例行程序local area network (LAN) 局域网local data 本地数据logic language逻辑语言logic program逻辑程序Mmachine language机器语言mailing list 邮件发送清单，邮件列表memory location 存储单元metal conductor金属导体microwave radio 微波无线电mnemonic address助记地址mnemonic name 助记名，缩写名modulated electrical impulse调制电脉冲Nname server 名称服务器network application网络应用程序network identifier 网络标识符neural network 神经网络Oobject code目标代码object-oriented database面向对象数据库object-oriented language 面向对象语言on-screen pointer 屏幕上的指针operating instructions操作指令operating system操作系统optical computer 光计算机Ppaper-tape reader 纸带阅读器parallel computing 并行计算parallel connection 并行连接parallel processing 并行处理pattern matching 模式匹配peer-to-peer model 对等模型personal computer个人计算机point-to-point communications点对点通信print server打印服务器processor chip处理器芯片program module程序模块program statement 程序语句program storage and execution程序的存储与执行program unit 程序单元programming language程序设计语言proprietary network 专有网络proprietary software 专有软件protocol suite 协议组，协议集Rradio telephone 无线电话recovered e-mail message恢复的电子邮件relational database managementsystem (RDBMS) 关系数据库管理系统relational database model关系数据库模型relational language 关系（型）语言requirements analysis and definition需求分析与定义ring topology环形拓扑结构run a computer program运行计算机程序Sserial connection串行连接signature file签名文件silicon substrate 硅衬底simple linear model 简单线性模型software life cycle软件生命周期（或生存周期）software maintenance tool软件维护工具software reuse软件复用source file 源文件source program源程序spreadsheet program电子数据表程序SQL 结构化查询语言star network 星形网络storage device存储设备storage register 存储寄存器system call 系统调用system design paradigm系统设计范例system documentation系统文件编制system evolution 系统演变system integration系统集成system specification 系统规格说明system validation testing 系统验证测试Ttelegraph key电报电键text formatting正文格式编排，文本格式化the storage and handling of data数据的存储与处理throwaway prototype 抛弃式原型token ring令牌环top-level domain (TLD) 顶级域名touch-sensitive region 触敏区transmission medium (或media)传输媒体two-dimensional table二维表Uunit testing 单位（或单元、部件）测试utility package 实用软件包，公用程序包utility program实用程序Vvacuum tube 真空管versatile logical element 通用逻辑元件very large-scale integrated circuit超大规模集成电路video display视频显示器video game 电子游戏voice recognition module 语音识别模块volatile memory易失性存储器Wwaterfall model瀑布模型wide area network (WAN) 广域网wire-based internal network基于导线的内部网络，有线内部网wireless communications无线通信wireless network无线网络word processor文字处理软件B版权法copyright law本地数据local data编译执行的语言compiled language 并行处理parallel processing并行计算parallel computing并行连接parallel connection拨号连接dial-up connection操作系统operating system操作指令operating instructionsC层次数据库模型hierarchical database model差分机difference engine常用情感符commonly used emoticon抄送行cc line超大规模集成电路very large-scale integrated circuit程序单元program unit程序的存储与执行program storage and execution程序模块program module程序设计语言programming language程序语句program statement处理器芯片processor chip触敏区touch-sensitive region传输媒体transmission medium (或media)传真机fax machine串行连接serial connection磁盘驱动器disk drive存储单元memory location存储寄存器storage register存储设备storage deviceD打印服务器print server单位（或单元、部件）测试unit testing 地址总线address bus点对点通信point-to-point communications点分十进制记数法dotted decimal notation点击图标click on an icon点阵打印机（针式打印机）dot-matrix printer电报电键telegraph key电子数据表程序spreadsheet program电子系统electronic system电子邮件常规e-mail convention电子邮件网规e-mail netiquette电子游戏video game顶级域名top-level domain (TLD)对等模型peer-to-peer modelE二进制记数法binary notation二维表two-dimensional tableF分布式数据库distributed database分散型网络decentralized network封闭式网络closed network蜂窝电话，移动电话，手机cell phon e/cellular telephone附件行Attachments line赋值语句assignment statementG个人计算机personal computer功能键，操作键function key关系（型）语言relational language关系数据库管理系统relational database managementsystem (RDBMS)关系数据库模型relational database model光计算机optical computer光缆fiber-optic cable广域网wide area network (WAN)硅衬底silicon substrateH函数式语言functional language函数语句function statement环形拓扑结构ring topology恢复的电子邮件recovered e-mail message汇编语言assembly languageJ机器间合作，计算机间合作inter-machine cooperation机器语言machine language基本输入/输出系统BIOS Basic Input/Output System基于导线的内部网络，有线内部网wire-based internal network基于组件的软件工程component-based softwareengineering (CBSE)激光打印机laser printer计算机程序员computer programmer计算机终端computer terminal简单线性模型simple linear model结构化查询语言SQL(Structured Query Language )解释程序interpreter program解释执行的语言interpreted language金属导体metal conductor进程间通信interprocess communication局域网local area network (LAN)K可执行程序executable program客户机/服务器模型client/server model库程序，程序库例行程序library routine宽带因特网访问broadband Internet accessL令牌环token ring逻辑程序logic program逻辑语言logic languageM密级信息classified information密件，秘密文件confidential document密送行bcc line面向对象数据库object-oriented database面向对象语言object-oriented language名称服务器name server模拟传输analog transmission模拟计算机analogue computer模式匹配pattern matching墨盒ink cartridge目标代码object codeP抛弃式原型throwaway prototype喷墨打印机nkjet printer平板扫描仪flatbed scanner平面文件flat file屏幕上的指针on-screen pointer瀑布模型waterfall modelQ签名文件signature file全局控制总线global control bus人工语言artificial language人工智能artificial intelligenceR软件复用software reuse软件生命周期（或生存周期）software life cycle软件维护工具software maintenance toolS商用现成软件Commercial off-the-shelf software设备驱动程序device driver神经网络neural network实体关系模型entity-relationship model (ERM)实用程序utility program实用软件包，公用程序包utility package视频显示器video display输入设备input device数据插入与删除data insertion and deletion数据的存储与处理the storage and handling of data数据库对象database object数据库管理系统(DBMS)database management system数据库管理员database administrator 数据库体系结构database architecture数据类型data type数据声明data declaration数据属性data attribute数据总线data bus数字电视digital television数字计算机digital computer数字用户线路DSLT探索式编程方法exploratory programming approach条件语句conditional statement调试程序debugging program调制电脉冲modulated electrical impulse通信卫星communication(s) satellite通用计算机general-purpose computer通用逻辑元件versatile logical element推理机inference engineW网吧cyber cafe网际协议地址，IP地址IP address网络标识符network identifier网络应用程序network application微波无线电microwave radio文件服务器file server文字处理软件word processor无绳电话cordless telephone无线电话radio telephone无线通信wireless communications无线网络wireless networkX系统规格说明system specification系统集成system integration系统设计范例system design paradigm系统调用system call系统文件编制system documentation系统演变system evolution系统验证测试system validation testing协议组，协议集protocol suite信息高速公路information superhighway星形网络star network需求分析与定义requirements analysis and definitionY演化开发过程evolutionary development process液晶显示（器）LCD (liquid crystal display)已删除电子邮件deleted e-mail以太网协议集Ethernet protocol collection易失性存储器volatile memory因特网编址Internet addressing因特网范围的目录系统Internet-wide directory system因特网服务提供商Internet service provider (ISP)因特网基础结构Internet infrastructure阴极射线管cathode ray tube音频信号audio signal应用程序application program硬件与软件支持hardware and software support邮件发送清单，邮件列表mailing list语音识别模块voice recognition module原子操作atomic operation源程序source program源文件source file运行计算机程序run a computer programZ载波检测，载波监听carrier sense真空管vacuum tube正文格式编排，文本格式化text formatting纸带阅读器paper-tape reader指令集instruction set中间程序，过渡程序intermediate program中间语言，中级语言intermediate language中央处理器central processing unit主机地址host address助记地址mnemonic address助记名，缩写名mnemonic name专用因特网连接dedicated Internet connection专有软件proprietary software专有网络proprietary network转发的电子邮件forwarded e-mail messages自主系统autonomous system总线拓扑网络bus topology network最终用户，终端用户end user。

面向对象语言
面向对象语言(Object-oriented programming language)是一种程序设计的范型，它以对象（具体指事物）为基础，以类（抽象）及其关联（关系）为构造方法，以封装、继承、多态等方式实现基于对象的数据及操作的封装、继承、重载和多态等特性，从而提高软件系统的可重用性、灵活性和扩展性。

目前常见的面向对象语言有Java、C++、Python、Ruby等。

面向对象语言具有以下优点：
1.可重用性：通过定义类，可以将对象的属性和行为独立于其他对象共同使用，提高代码的重用性。

2.封装性：对外部数据和操作实现隐藏，保护数据安全，使不同部分的程序之间互不干扰。

3.继承性：通过定义子类，可以继承父类的属性和操作，减少代码量，降低程序的复杂度。

4.多态性：同名操作可以通过参数类型或个数的不同来进行区分，提高了代码的灵活性和可扩展性。

当然面向对象语言也有其局限性，如：
1. 需要研究和掌握抽象化、类、继承、封装、多态等面向对象术语及思想。

2. 对于简单的程序代码，使用面向对象也许并不是最佳选择。

总的来说，面向对象语言是一种有效的程序设计方法，通过合理地设计类与对象，从而使程序具有更好的可读性和维护性。

2Some Informationo Lecturingn C/C++ Language n Artificial Intelligence n Specialized Englisho Phone numbers and emailn Office: A0816n Phone: 84706003-3816n Email: eecc2012@3Textbooko 书名：C 语言教程（英文版·第4版）o 原书名：A Book on C:Programming in Co 作者：(美)Al Kelley, Ira Pohl o 出版社:China Machine Pres s4Professor of Computer and Information Scienceso Ira Pohl is a Professor of ComputerScience at the University of California, Santa Cruz.o His current research is in object-orientedprogramming(OOP) and topics in software methodology. He has written widely on programming in C, C++，C# and Java.o His research interests include artificialintelligence (AI), the C#, C, C++ and Java programming languages, practical complexity problems, heuristic search methods, etc..5Reference Readingo 书名：C 语言的科学和艺术（英文版）o 原书名：The Art andScience of C:A Library Based Introduction to Computer Science o 作者：Eric S.Robertso 出版社:China Machine Pres s6Reference Readingo 书名：C 程序设计语言（第2版·新版）o 原书名：The C ProgrammingLanguageo 作者：(美)Brian W.Kernighan,Dennis M.Ritchieo 出版社: Prentice-HallInternational , Inc.7Course administrationo Class hours ：72 Credits ：4n Teaching hours ：48 hours (3 credits)n Practice hours ：24 hours (1 credits)o Grading system ：100n Final exam: 60%n Homework and Quizz: 15%n Projects: 25%Course administrationo Class is 4hours of lecture a week, Monday andWednesday at 13:30pm and 8:00amo 4 hours of practice a week ,6 weeks from 6th~11th week o 8hours a week of outside-the-class.9Why do we learn C language?o Today is the era of java and .net.oC is the fundament of OS. The kernel of Unix, Linux and Windows are written by C. Windows API is the interface of C functions. Unix/Linux applications are developed by C.oIf you want to be the superior of programmer, you must learn C language.oC# derived from C/C++What skills will you acquire?o You’re going to be able to write.o You’re going to be able to read.o Understand abilities and limits.o Understand what you can and cannot do.11How to study C programming:Some proverbso Standardization of formatn Well begun, half done.n A year ’s plan starts spring.o Have patiencen A workman must first sharpen his tools if he is to dohis work well.n Right tool for the right job.o Debug routinen Everything has a hard beginning.n Practice makes perfect.To follow, without halt, one aim:there the secret of success.12How to study C programming:o 1. Read all assigned reading in the textbook.--Not just once.--one paragraph at a time.--close the book, summarize the paragraph you just read.--If you could not summarize it quickly and accurately,read it again .o 2. Read your lecture notes in the same way.Type in all the programs you saw in class and make sure you understand them.o 3. Read the documentation of strcpy , strcat , strcmp ,malloc , calloc , strlen , printf , sprint , sscanf etc. Know how to find the documentation of any C library function and what is meant by "the documentation".o 4. Read your homework and make sure you know how itworks. The exams will definitely include several questions about the homework programs.13What I expect from you as a student:o Show up for classo Show up for class on timeo Know what the topic is for that dayo Have already read the corresponding part of the textbook (see the lecture schedule)o After the class meets, go over the material again (textbook, and notes, if any)o Do your homework (and on time!)o Do your own homework by yourself . (You can discuss it orally but you must do your own writing.)o Arrange your schedule so that you have identifiable hours each week to spend on this course.oWork at a steady pace throughout the semester instead of in frantic bursts just before the final exam.14What will we learn?o Program o Functionsn Declarationso Constant o Variablen fundamental :int, char, float, double n structured: array, struct, union n pointern Statementso assignmento control: if, for, do, while,…o compound o null150 Starting from Zero2 Lexical Element,Operators, and C System 3The Fundamental Data Types 4Flow of Control 5Functions6Arrays, Pointers and Strings7Bitwise Operators and Enumeration Types 8The preprocessor 9Structures and Unions 10Structures and List Processing11Input/Output and the Operating System13 Moving from C to C++Contents 16o Some termsn Computer language n Programn Programming n Algorithmo Program ’s Constitutionn Some representation of fundamental data n Give instructions to computer(decription of recipe)C/C++ Language17o What is the program?n data structure+algorithm=program n data structure+algorithm+structured programming method+language tool= programo Three basic structuresn Sequential n conditional n IterationC/C++LanguageNikiklaus Wirth——Computer Scientist18o 0.1 C ’s background o 0.2 C ’s Characteristic o 0.3 ANSI C Standard o 0.4 From C to C++o 0.5 From C and C++ to Java0 Starting from Zero19The basic organization of a computer system0.1 C ’s background Arithmetic sectionStorage sectionControl section Input device Output deviceresultprogramdataCPU20Machine languagesAssembly languagesHigh-level languageProcedure -oriented Object-oriented0.1 C ’s backgroundThe development of programming languages211.In the mid-1970s,UNIX spread throughout BellLabs.2.By 1980,several C compilers were put forward onthe market.3.By now,there are many versions of C languages.0.1 C ’s background The origin of C language 22True dialogueArtificial intelligence “ dialogues”Command languages(as in OS)Problem-oriented languages(Fortran, Pascal)Machine-oriented languages(BCPL,B)Assembly languagesHardware0.1 C ’s backgroundThe place of the C languageþýüþýülow-levelHigh-levelconcrete abstractdetailedgeneralpastfuture C23Algol60 (1960,an international committee)CPL (1963,Cambridge & Univ.of London)BCPL (1967, Martin Richards)B (1970, Ken Thompson)C (1972, Dennis Ritchie)0.1 C ’s background The development of the C language240.2 C ’s characteristicp C is a small language Keyword p C is the native language of Unix p C is portable Pascal p C is terse Operator p C is modularp C is the basis for C++ and Java p C is efficient on most machinesp C is not without criticism0.3 ANSI C Standard 26p C often serves as the kernel for more advanced or morespecialized languages.p C++ is an object-oriented language,it is the extension of C.0.4 From C to C++27p Java was designed for work on the Internetp It allows the programmer to write secure and portableprograms that can be downloaded from the Internet and run on your local machine.p Java borrows ideas from both C and C++ and is designed to run in a machine-and system-independent manner.0.5 From C and C++ to Java 28o Operating system o Source file o Text editor o Compiler o Object codeProgramming and preparation29We must do: 1. Edit it (*.c)2. Compile it (*.obj)3. Run it (*.exe)It depends on the system we are using.Programming and preparation 30Programming and preparation31VC++6.0Programming and preparation32“File ”→“New ”33“Files ”→“C++ Source Files ”34“File ”→“Save ”35“Build ”→“Compile test1.c ”36“Build ”→“Build test1.exe ”37“Build ”→“Execute test1.exe ”3839sea1.c#include <stdio.h>int main (){printf(“from sea to shining C\n ”);return 0;}Examplesfrom sea to shining CLibrary function 40sea2.c#include <stdio.h>void main(){printf(“from sea to ”);printf( “shining C ”);printf(“\n ”);}Examplesfrom sea to shining C41sea3.c#include <stdio.h>void main(){printf(“from sea\n ”);printf( “to shining \nC\n ”);}Examplesfrom sea to shining C42******************* from sea ** to shining C *******************43sea4.co #include <stdio.h>o void main()o {o printf("\n\n\n\n\n\n\n\n\n\n");o printf(" ******************\n");o printf(“* from sea *\n");o printf(“* to shining C *\n");o printf(" ******************\n");o printf("\n\n\n\n\n\n\n\n\n\n");o}Examples 44n miles and yards, kilometers. n Convert yards to miles, divide by 1760.0n Convert miles to kilometers, conversion factor 1.609n miles=yards/1760.0;nkilometers=1.609*miles;ExamplesIn English units, a marathon is defined to be2638542.245/* marathon .c The distance of a marathon in kilometers.*/Examples#include <stdio.h>void main(){ int miles,yards;float kilometers;miles=26;yards=385;kilometers=1.609*(miles+yards/1760.0);printf(“\nA marathon is %f kilometers.\n\n”, kilometers);}A marathon is 42.185969 kilometers.46/*The distance of a marathon in kilometers.*/Examplesp Convert the distance of a marathon in miles and yards to kilometers p int ,floatp V ariables must be declared at the beginning of the program p Identifier consists of a sequence of letters,digits,andunderscores,but may not start with a digit.p Comment p Semicolonp Assignment statement p precedence47Homeworko Write an interactive program that converts pounds andounces to kilograms and e symbolic constants that are defined at the top of the file outside of main().o 2. For a three-figure integer, get its unit's place , ten ’splace and hundred's place figure.o pute the roots of quadratic equation ：ax 2+bx+c=0o 4.Input the three edges of a triangle, compute its area.o 5. Compute the BODY MASS INDEX(BMI)t= weight (kg)/height (m x m)ïïïîïïïíì³<£<£<£<II 0Obese .30 I 9Obese .9252t9Overweigh .42329Normal .225.18ht 5Underweig .18t t t t t 48Thank you！49Keywords( standard C:32)auto break case char const continue default do double else enum extern float for goto if int long register return short signed sizeof static struct switch typedef unsigned union void volatile while50Keywords(C++:32)bad_cast bad_typeid bool catch classconst_cast delete dynameic_cast except explicitfinally friend inline mutable namespace new operator private protected public reinterpret-cast static_cast template this throwtrue try type-info typeid typename using virtual<51Control statements(9)if( )~else~for( )~while( )~do~while( )continue break switch goto return<52C & PascalC Pascal{ } BEGIN….END if(e) s; IF(e) THEN sint i ; VAR i:INTEGERint a[10]; VAR a:ARRAY[1..10] OF INTEGER int f(); FUNCTION f():INTEGERint *p;VAR p:-INTEGER<53Operatorsarithemetic：+ -* / % ++ --relational：< <= == > >= !=logical：！&& ||bitwise：<< >> ~ | ^ &assignment：= += -= *= /= %= &= ^= |= <<= >>=conditional：?:comma：,pointer：* &Bit count：sizeof case：(type-name）member：. ->index：[]others：( ) -<54Data TypesData typestandardstructure d pointer voidtypedefnumericchar enumintegral realfloatdoubleshort long intarraystruct union <55portableif (x>0) then BEGIN A:=1;B:= 2END;#define THEN #define BEGIN {#define := =#define END ; ;}if (x>0) {A=1;B=2;}<。

低级语言和高级语言（Low level language and high-levellanguage）13.3.1 low-level language and high-level languageComputer programming languages can be divided into two types: low level language and high-level language.1. low level languageLow-level languages provide the ability to manipulate the underlying hardware of a computer system. A skilled programmer usually uses low-level languages to write bottom system software such as operating systems, device drivers, and compilers. Low-level languages use the CPU instruction set to directly call processors, registers, and memory addresses, and maintain very high efficiency in these operations. Since different CPU provides different instruction sets, low-level languages rely on computers.Low level languages are very flexible and efficient in processing hardware, but writing programs requires a more thorough understanding of operating systems and hardware, usually only by a few professional programmers.(1) machine languageA machine language is a programming language that exists in binary form and can be directly executed by a computer. Every sentence in a machine language is a machine instruction consisting of binary operands and operands.Machine language is difficult for people to understand and difficult to master. It is only used in the initial stage of computer development.(2) assembly languageAssembly language uses some mnemonic symbols to represent the instructions and data in machine language, and makes the machine language symbolic. Therefore, sometimes assembly language is also called symbolic language. Different types of computer systems usually have different assembly languages.Assembly language before execution, it is necessary to use assembly system to translate assembly language into machine language. As shown in figure 13.9.2. high-level languageThe high-level language also provides the instructions or statements needed to write programs, but these statements are very close to human language and are quite functional, and you can use them to write large application software systems. Common computer programming languages are mostly high-level languages such as BASIC, C, C++, FORTRAN, PASCAL, Java, and so on.Unlike low-level language, a high-level program can run on different computer systems, this feature greatly reduces the burden of programmers, so they do not understand the underlying computer knowledge, and will focus on the application of logicsystem.Programs written in high-level languages do not run directly on the operating system. They need to translate program code into computer languages that can be directly run by the computer, depending on the computer system. This work is generally handled automatically by high-level language systems.Generally, program code written in high-level language is called source program, and the translated machine language code is called object program".(1) procedural languageA program written in procedural languages that contains a series of statement descriptions that tell the computer how to execute these statements for specific tasks. The process of the language program need to design specific algorithms, process design program we mentioned earlier, it is mainly aimed at the process of the language, we are most common programming language the process of language, such as BASIC and C etc..(2) declarative languageDeclarative language is a rather special language, which differs greatly from the idea of procedural language. The definition of language programmers only need to specify the rules and conditions, do not need to describe the specific means of language's own built-in algorithm, can put these rules to explain specific steps to solve the problem. That is to say, when you write a program in declarative language, you just tellthe computer what to do without telling it how to do it.The SQL language in the database management system is an illustrative language. For example, the user wrote the SQL statement "SELECT * FROM TB", the function of this statement to output all records of the TB table. You can see, this statement does not describe how to query, but tell the system to check what, the system received this instruction, according to the scheduled algorithm to complete the query, and output results.Figure 13.12 is a Oracle SQL Plus interface that runs the SQL statement.Figure 13.12 Oracle SQL Plus running interface(3) scripting languageScripting languages are extensions that some application systems provide to extend the functionality of the application system. Users can write scripts to embed into the application system and accomplish certain tasks. Scripting languages run entirely on application systems and cannot run separately.For example, HTML, VBScript, and JavaScript are scripting languages running on browsers, using these scripts to write colorful web programs.The macro language in Microsoft Office is also a scripting language, as shown in figure 13.13. This macro language has exactly the same syntax as VB, and users can use these macrosto extend the application of Office. Incidentally, the Office macro language also provides an opportunity for some people who have an ulterior motive, in recent years a variety of macro virus is rampant everywhere, use the Office macro language.Figure 13.13 Microsoft Office macro editorIn general, scripting languages are relatively simple and provide a lot of control options.(4) object oriented languageObject oriented language is a programming language based on object oriented method. The basic idea of object-oriented method is: the objective world is composed of many kinds of objects, each object has its own internal state and the motion law of interaction and connection between different objects of different kinds of system.Object oriented language reflects the objective world more intuitively, and facilitates the decomposition of complex problems into a number of sub problems. Therefore, it has been widely used in the development of large-scale software in recent years.Object oriented languages generally include the following concepts:Object: an object is made up of attributes and operations. Attributes and operations describe the characteristics of an object.Class: a class is a collection of objects with the same characteristics, and an object is an instance of a particular class.Encapsulation: hide the internal details of objects as much as possible. Only some interfaces of an object are provided to the outside.Inheritance: hierarchies exist between classes, and child objects have all the properties of a parent class.Message: an object sending a service request to another object is called a message. Messages are means of communication between objectsPolymorphism: refers to an operation that operates on different objects and can have different operations, depending on the class information that the object determines which operations to perform.C++, Java, and are all object oriented languages.13.3.2 interpreted language and compiled languageWhen a computer translates a source program into an object program, there are two ways of translating, one is "Interpreting", and the other is "compiling". Corresponding to the two translation methods, high-level language can be divided into interpretative language and compiled language.1. explanatory languageInterpreted languages use interpreters to generate target programs. Run an interpretive language program, an interpreter reads a statement, put it into executable machine language, and sent to the processor; and then read the next statement, to continue the process until the end. Explain the characteristics of language is the implementation of the translation of a sentence by sentence, translating, so explain written language program execution speed is relatively slow, especially multi loop program loop is repeated several times to explain, the efficiency is very low.The process in which a statement is interpreted by an interpreted language, as shown in figure 13.10.The more familiar BASIC and scripting languages are explanatory languages. But some advanced BASIC environments, such as Visual BASIC, now provide compilation capabilities.2. compiled languagePrograms written in compiled languages must be passed by the compiler to translate the source program into equivalent object programs before they run, and then execute the machine code. The compiled target program can run directly from the compiler environment under the operating system. Many compilers provide the compiler optimization function to optimize the speed of the target program under different computer systems, so the compiler language runs more efficiently.In a compiled language, programs written in compiled language contain any syntax errors,Then the compiler can not pass, and can not run and view the results.The compiler's compilation process is usually divided into two steps:1. compiler: the compiler converts the source program to the target program, but the target module does not allocate the absolute address of the memory and can not be executed directly.2. links: the compiler converts all relevant objects and function libraries into a loader that assigns addresses and belongs to executable programs.The entire process of compiling a compiler is shown in figure 13.11.Both the C and C++ languages belong to the compiled language.Java is a very special language, is between the compilation and explanation, Java can be compiled to generate binary file binary file, but this can not directly run in the operating system, through the Java virtual machine to explain real operation.。

c++常用英语单词c++常用英语单词A抽象数据类型abstract data type 抽象abstraction累加accumulating 实际变元actual argument实际参数actual parameter 地址运算符address operator算法 algorithm 功能模型al model运算与逻辑单元ALU 分析 analysis应用软件application software 参数/变元argument算术运算符arithmetic operators 基类ase class汇编程序assembler 汇编语言assembler language赋值运算符assignment operator(s) 赋值语句assignment statement综合性associativity 原子数据类型atomic dataB备份件backup copies 大o表示法Big O notation测试的基本规则basic rule of testing 二分法查找 binary search位bit 函数体 boday引导boot 字节bytesC被调函数called 调用函数calling类型转换cast 字符值character s类class 类层次class hierarchy类的成员class members 类的作用范围class scope编写代码coding 注释comments编译型语言compiled language 编译程序compiler编译时错误compile-time error 复合语句compound statement计算机程序computer program 条件 condition控制单元 control unit 转换运算符conversion operator 构造函数costructor 记数countingD字段data field 数据文件data file数据隐藏data hiding 数据成员data member数据类型data type 声明部分declaration section 声明语句declaration statement 自减运算符decrement operator缺省复制构造函数default copy constructor 缺省构造函数default constructor函数定义 definition 定义语句definition statement 派生类derived class 桌面检查desk checking析构函数destructor 文档编写documentation双精度数double-precision number 动态绑定dynamic hinding动态模型dynamic modelE回显打印echo printing 封装encapsulation转义序列escape sequence 交换排序法exchange sort表达式expression 外部文件名external file name F假条件false condition 域宽操纵符field width manipulator文件访问file access 文件组织形式file organization 文件流 file stream 浮点数floating-point number 软盘floppy diskette 流程图flowchart形式变元formal argument 形式参数formal parameter友元函数friendG全局作用的范围global scope 全局变量global variableH硬盘hard disk 硬件hardware函数首部 header 头文件header file十六进制hexadecimal 高级语言high-level languageI标识符identifier 实现implement实现部分implementation section 自增运算符 increment operator下标index 下标变量indexed variable 间接寻址indirect addressing 无限循环infinite loop间接寻址运算符 indirection operator 继承性inheritance内联成员函数inline member 输入文件流 input file stream实例变量instance variables 解释型语言interpreted language解释程序interpreter 调用invocation整数值iteger 循环结构iteration输入/输出单元 I/O unitJ对齐justificatingK关键字段key field 关键字keywordL左值l 线形查找linear （sequential）search链表linked list 局部作用范围local scope局部变量local variable 逻辑错误logic error低级语言low-level languageM机器语言machine language 魔术数magic number操纵符manipulator 数学头文件mathematicallibrary成员函数 member s 成员式赋值memberwise assignment 内存堆栈memory stack 内存单元 memory unit微处理器microprocessor 混合表达式mixed-mode expression 助记符mnemonic 模型model模块module 取模运算符modulus operator 多重继承multiple inheritanceN已命名常数named constant 嵌套循环nested loop空字符null character 空语句null statementO面向对象的语言object-oriented language 对象object八进制octal 偏移量offset一维数组one-dimensional array 操作码opcode操作系统operating system 运算符函数operator输出文件流 output file stream 函数的重载 overloadingP参数parameter 值传递pass by引用传递pass by reference 指针pointer指针变量pointer variable 多态性polymorphism后判断循环posttest loop 优先级 preccedence先判断循环pretest loop 私有private面向过程的语言procedure-oriented language 汇编语言programming language程序设计progremming 提示prompt函数的原形 prototype 伪代码pseudocode程序验证与测试program verification and testing公有publicQ快速排序法quicksortR右值r 随机访问 random access记录recored 递归传递recursive细化refinement 循环结构repetition循环语句repetition statement 返回语句return statement运行时错误run-time errorS换算scaling 作用范围scope辅存secondary storage 选择结构selection选择排序法selection sort 标记sentinel顺序组织形式sepuential organization 顺序结构sequence简单继承simple inheritance 单维数组single-dimensional array软件software 软件工程software engineering软件开发过程software development procedure 软件维护software maintenance源代码soure code 源程序source program字符串变量sring variable 静态绑定static hiding静态类数据成员static class data member 存储类型storage class结构体structure 结构体成员structure member函数占位符stub 下标sub下标变量subed variable 语法syntax语法错误syntax error 符号常数symbolic constant 系统软件system softwareT函数模板 template 模板前缀template prefix测试testing U 文本文件text filethis指针this pointer 跟踪tracing类型转换type conversions 二维数组two-dimensional array 类型转换构造函数 type conversion constructor 二进制补码two’s complem entU联合体unionV变量variable 变量作用范围variable scope可变条件循环variable condition loop 二进制文件vinary file虚函数virtual整理BY manucjj发音：Pointers（指针）references（引用）casts（类型转换）arrays（数组）constructors（构造）abstraction抽象action行动action-oriented面向行动analysis分析ANSI/ISO standardＣ++标准Ｃ＋＋arithmetic and logic unit(ALU)算术和逻辑单元arithmetic operators 算术操作符assenbly language汇编语言association关联associativity of operators地址操作符assignment operator赋值操作符attribute属性attributes of an object对象的属性behavior行为binary operator二元操作符C++ standard library C++标准库compile error 编译错误compiler编译器component组件date member 数据成员distributed computing 分布式计算editor编辑器encapsulation封装execution-time error执行期错误fatal error致命错误flow of control控制流程function函数identifier标识符information hiding信息隐藏inheritance继承instantiate实例化interface接口interpreter解释器linking连接logic error逻辑错误modeling建模multiple inheritance多重继承multiprogramming多路程序Object Management Group（OMG）对象管理组object-oriented analysis and design（OOAD）面向对象分析和设计operator associativity操作符的结合性precedence优先级preprocessor预处理器prompt提示pseudocode伪代码satement语句structured programming结构化编程syntax error语法错误Unified Modeling Language（UML）统一建模语言user-defined type 用户自定义类型variable变量名algorithm算法block代码块case label标签infinite loop无限循环delay loop延迟循环parameterized stream manipulator参数化流操纵元syntax error语法错误composition合成Object Constraint Language（OCL）对象限制语言argument in a function call函数调用中的参数automatic storage class自动存储类call-by-reference按引用调用coercion of arguments强制类型转换dangling reference悬挂引用enumeration枚举access function访问函数class scope类作用域constructor构造函数destructor析构函数global object全局对象header file头文件interface to a class类的接口proxy class代理类rapid applications development（RAD）快速应用程序开发source-code file源代码文件handle句柄abstract data type（ADT）抽象数据类型first-in-first-out（FIFO）先进先出iterator迭代器member access specifiers成员访问说明符pop（stack operation）弹出（堆栈操作）forward declaration 提前声明1.int:integer,整数2.const:constant,变量3.Variable:变量4.IDE:集成开发环境5.Visual C : 微软雄司开发的C言语C集成开发环境软件6.Turbo C: Borland雄司开发的c编译器7.GCC:Linux下的c编译器8.C Builder: Borland雄司开发的c言语IDEpile:编译piler:编译器11.float:浮点数,实数12.double:双精度浮点数,实数13.debug:调试14.Dennis Ritchie: C言语的创造者15.Bjarne Stroustrup : C言语的创造者17.The C Programming Language: Dennis Ritchie写的C编程言语,C言语圣经17.the C Programming Language: Bjarne Stroustrup 写的c编程言语,c 圣经19.ANSI C: C言语国际准则,也称为ISO C 20. AT T: 美国电报德律风雄司21.Bell Labs: 贝尔实验室,c和C 的创造地,隶属于AT T22.Array:数组23.MSDN:微软开发者网络24.MSDN Libaray: 微软开发者技术库25.MFC:微软基础类26.Visual Studio:微软开发的编程IDE,包括VC,VB,VC井等组件27.Bite:字节,存储容量单位28.KB:千字节29.MB:兆字节30.file:文件31.IO:输进输出(input,output) 32.class:类33.object:东西33.loop:循环体34.operator:运算符35.function:函数36.macro:宏3 7.define:界说38.Microsoft:美国微软雄司39.Windows:微软开发的看窗作零碎,用C言语编写40.math:数学41. .c:C源代文件的后缀名42. .h:头文件的后缀名33. .cpp :c加加源代文件后缀名34 :包括35. breakpoint:断点。

面向问题的语言
面向问题的语言(Problem-oriented language)是一种专门用于描述问题的语言。

这种语言通常包括一系列的词汇和语法规则，用于表达问题的各个方面，如问题的定义、问题的原因、问题的解决方案等。

面向问题的语言可以用于多种领域，例如在医疗领域中，医生可以使用这种语言来描述病人的症状和问题，在商业领域中，业务分析师可以使用这种语言来描述业务问题，以便于开发团队理解和解决这些问题。

以下是一些常见的面向问题的语言的例子：
* 医疗领域中的SOAP(Subjective, Objective, Assessment, Plan)是一种常见的面向问题的语言，用于描述病人的问题和医生的诊断计划。

* 在业务流程管理(BPM)领域中，BPMN(Business Process Model and Notation)是一种面向问题的语言，用于描述业务流程和流程模型。

* 在软件开发领域中，面向问题的方法(Problem-oriented approach)是一种软件开发方法，它强调将问题分解为小块，并为每个小块定义任务和解决方案。

总的来说，面向问题的语言是一种非常有用的工具，可以帮助人们更好地理解和解决各种问题。

Computer Language and ProgrammingI. IntroductionProgramming languages, in computer sc ienc e, are the artific ial languages used to write a sequenc e of instructions (a computer program) that c an be run by a computer. Similar to natural languages, such as English, programming languages have a voc abulary, grammar, and syntax. How ever, natural languages are not suited for programming computers bec ause they are ambiguous, meaning that their vocabulary and grammatic al struc ture may be interpreted in multiple ways. The languages used to program computers must have simple logic al structures, and the rules for their grammar, spelling, and punctuation must be prec ise.Programming languages vary greatly in their sophistic ation and in their degree of versatility. Some programming languages are written to address a partic ular kind of computing problem or for use on a partic ular model of computer system. For instanc e, programming languages such as FORTRAN and COBOL w ere written to solve certain general types of programming problems—FORTRAN for sc ientific applic ations, and COBOL for business applic ations. Although these languages were designed to address spec ific categories of computer problems, they are highly portable, meaning that they may be used to program many types of computers. Other languages, such as mac hine languages, are designed to be used by one spec ific model of computer system, or even by one spec ific computer in c ertain researc h applications. The most c ommonly used programming languages are highly portable and can be used to effectively solve diverse types of computing problems. Languages like C, PASCAL and BASIC fall into this c ategory.II. Language TypesProgramming languages can be c lassified as either low-level languages or high-level languages. Low-level programming languages, or machine languages, are the most basic type of programming languages and can be understood directly by a c omputer. Machine languages differ depending on the manufacturer and model of computer. High-level languages are programming languages that must first be translated into a machine language before they c an be understood and processed by a computer. Examples of high-level languages are C, C++, PASCAL, and FORTRAN. Assembly languages are intermediate languages that are very c lose to mac hine languages and do not have the level of linguisticsophistic ation exhibited by other high-level languages, but must still be translated into mac hine language.1. Machine LanguagesIn mac hine languages, instructions are written as s equenc es of 1s and 0s, called bits, that a computer c an understand direc tly. An instruc tion in mac hine language generally tells the computer four things: (1) where to find one or two numbers or simple pieces of data in the main computer memory (Random Access Memory, or RAM), (2) a simple operation to perform, suc h as adding the two numbers together, (3) where in the main memory to put the result of this simple operation, and (4) where to find the next instruc tion to perform. While all exec utable programs ar e eventually read by the computer in mac hine language, they are not all programmed in machine language. It is extremely difficult to program directly in machine language bec ause the instructions are sequenc es of 1s and 0s. A typic al instruc tion in a mac hine language might read 10010 1100 1011 and mean add the contents of storage register A to the contents of storage register B.2. High-Level LanguagesHigh-level languages are relatively sophisticated sets of statements utilizing w ords and syntax from human language. They are more similar to normal human languages than assembly or machine languages and are therefore easier to use for writing c omplic ated programs. These programming languages allow larger and more complic ated programs to be developed faster. How ever, high-level languages must be translated into machine language by another program c alled a compiler before a c omputer can understand them. For this reason, programs written in a high-level language may take longer to execute and use up more memory than programs written in an assembly language.3. Assembly LanguagesComputer programmers use assembly languages to make mac hine-language programs easier to write. In an assembly language, each statement corresponds roughly to one mac hine language instruction. An assembly language statement is composed w ith the aid of easy to remember commands. The command to add the c ontents of the storage register A to the c ontents of storage register B might be written ADD B, A in a typical assembly language statement. Assembly languages share certain features w ith mac hine languages. For instance, it is possible to manipulate spec ific bits in both assembly and machinelanguages. Programmers use assemblylanguages when it is important to minimize the time it takes to run a program, because the translation from assembly language to machine language is relatively simple. Assembly languages are also used when some part of the c omputer has to be c ontrolled direc tly, such as individual dots on a monitor or the flow of individua l c harac ters to a printer.III. Classific ation of High-Level LanguagesHigh-level languages are c ommonly c lassified as proc edure-oriented, functional, objec t-oriented, or logic languages. The most common high-level languages today are proc edure-oriented languages. In these languages, one or more related blocks of statements that perform some complete function are grouped together into a program module, or proc edure, and given a name such as “proc edure A.” If the same sequence of operations is needed elsewhere in the program, a simple statement can be used to refer bac k to the proc edure. In essence, a proc edure is just amini- program. A large program c an be c onstructed by grouping together procedures that perform different tasks. Proc edural languages allo w programs to be shorter and easier for the c omputer to read, but they require the programmer to design eac h procedure to be general enough to be usedin different situations. Func tional languages treat proc edures like mathematic al functions and allow them to be processed like any other data in a program. This allows a much higher and more rigorous level of program construction. Func tional languages also allow variables—symbols for data that c an be spec ified and changed by the user as the program is running—to be given values only once. This simplifies programming by reduc ing the need to be concerned w ith the exac t order of statement execution, sinc e a variable does not have to be redec lared , or restated, eac h time it is used in a program statement. Many of the ideas from functional languages have become key parts of many modern procedural languages. Object-oriented languages are outgrowths of functional languages. In objec t-oriented languages, the c ode used to write the program and the data proc essed by the program are grouped together into units called objec ts. Objec ts are further grouped into c lasses, which define the attributes objects must have. A simple example of a c lass is the c lass Book. Objects w ithin this c lass might be Novel and Short Story. Objec ts also have certain functions assoc iated w ith them, called methods. Thecomputer accesses an objec t through the use of one of the object’s methods. The method performs some ac tion to the data in the object and returns this value to the computer. Classes of objec ts can also be further grouped into hierarchies, in whic h objects of one class can inherit methods from another c lass. The structure provided in object-oriented languages makes them very useful for complic ated programming tasks. Logic languages use logic as their mathematic al base. A logic program consists of sets of facts and if-then rules, whic h spec ify how one set of facts may be deduced from others, for example: If the statement X is true, then the statement Y is false. In the execution of such a program, an input statement can be logic ally deduced from other statements in the program. Many artific ial intelligenc e programs are written in suc h languages.IV. Language Structure and ComponentsProgramming languages use spec ific types of statements, or instructions, to provide func tional structure to the program. A statement in a program is a basic sentenc e that expresses a simple idea—its purpose is to give the computer a basic instruction. Statements define the types of data allow ed, how data ar e to be manipulated, and the w ays that proc edures and functions work. Programmers use statements to manipulate common components of programming languages, such as variables and macros (mini-programs within a program). Statements known as data dec larations give names and properties to elements of a program c alled variables. V ariables c an be assigned different values w ithin the program. The properties variables c an have are c alled types, and they inc lude such things as w hat possible values might be saved in the variables, how much numeric al accuracy is to be used in the values, and how one variable may represent a collection of simpler values in an organized fashion, such as a table or array. In many programming languages, a key data type is a pointer. V ariables that are pointers do not themselves have values; instead, they have information that the computer can use to loc ate some other variable—that is, they point to another variable. An expression is a piec e of a statement that describes a series of c omputati ons to be performed on some of the program’s variables, such as X+Y/Z, in which the variables are X, Y, and Z and the computations are addition and division. An assignment statement assigns a variable a value derived from some expression, while c onditional statements spec ify expressions to be tested and then used to selec t whic h other statements should be executed next.Proc edure and function statements define c ertain bloc ks of code as procedures or functions that can then be returned to later in the program. These statements also define the kinds of variables and parameters the programmer c an c hoose and the type of value that the c ode will return when an expression acc esses the procedure or function. Many programming languages also permit mini translation programs c alled macros. Macros translate segments of c ode that have been written in a language struc ture defined by the programmer into statements that the programming language understands.V. HistoryProgramming languages date back almost to the invent ion of the digital c omputer in the 1940s. The first assembly languages emerged in the late 1950s w ith the introduc tion of commerc ial c omputers. The first proc edural languages were developed in the late 1950s to early 1960s: FORTRAN, created by John Bac kus, and then COBOL, created by Grac e Hopper The first functional language w as LISP, written by John McCarthy4 in the late 1950s. Although heavily updated, all three languages are still w idely used today. In the late 1960s, the first objec t-oriented languages, such as SIMULA, emerged. Logic languages bec ame w ell known in the mid 1970swith the introduction of PROLOG6, a language used to program artific ial intelligenc e softw are. During the 1970s, proc edural languages c ontinued to develop w ith ALGOL, BASIC, PASCAL, C, and A d a SMALLTALK w as a highly influential object-oriented language that led to the merging ofobjec t- oriented and procedural languages in C++ and more rec ently in JAVA10. Although pure logic languages have dec lined in popularity, variations hav e bec ome vitally important in the form of relational languages for modern databases, such as SQL.计算机程序一、引言计算机程序是指导计算机执行某个功能或功能组合的一套指令。

⽼饭新炒：objectbased、objectoriented与弱类语⾔说⽼饭，是因为以前就折腾过这些问题了；新炒，则是指放到如今变得流⾏的那些可以动态修改对象的语⾔的环境下。

弱类在这⾥是指这些语⾔通过忽视固定类从⽽带来了表达能⼒的变化；当然，可以包括根本不带有类型系统的语⾔。

（强烈警告：这⾥讨论的弱类，和语⾔的强类型与否，是两码事！同样，类型系统是指管理⾃定义类型的系统。

）Update：鉴于此⽂原来的版本⽤作起头的信息来源不怎么靠谱，重新编辑为以作为讨论的起点[1]。

⾸先⼤家可以在Google和Baidu上搜索object based，看看⽐较⼴泛的观点是什么。

上述论⽂中提到，object-oriented = objects + classes + inheritance（同时这⼀观点在最近版本的OOAD/A仍然采⽤（已确实），同时这些论⽂或著作中都谈到了多态）。

所以⼀些⼈说，是不是oo，关键要看是不是多态（后两者提供了多态的⼿段）。

虽然这种理解在过去主要被⽤在基于class的语⾔之中，但是！这种认识并⾮仅仅是在静态语⾔社区的共识，⽽是整个⾯向对象社区都在讨论的。

即便没有编译过程、没有类型系统，对于⼀个对象我们可以认为存在⼀个“隐式”的类型，只是咱们必须按照已知的信息⼈为的约束⾃⼰⾏为；如果具体⾏为（⽽不仅仅是其接⼝）都已经被固定，在运⾏前（相对于此⽂提到的编译期）我们就知道所有和它有关的*确切*信息，这就不具有多态性。

鉴于弱类语⾔中常见的对这种“隐式类型”进⾏更改，为了使得这种灵活性与⾯向对象的特征进⾏区别，我们可以做出如下考虑：即使我们通过修改这个对象产⽣了⼀个新的“隐式”类型（⽐如添加了⼀个⾏为），新的“隐式”类型会怎么⼲，如果在任何时候都是确定的，这仍然是object based的路⼦。

但如果我们变更⼀个隐式类型A的具体⾏为，却不修改其接⼝，这虽然也产⽣了⼀个隐式类型A1，但它隐藏在隐式类型A的后⾯；和在拥有显式类型的语⾔中类似，我们使⽤时并不知道确切的类型A1，⽽认为还是在使⽤的A，这就有了多态的能⼒。

面向对象程序设计课堂笔记一、什么是面向对象程序设计。

面向对象程序设计（Object-Oriented Programming，OOP）是一种编程范式，它将现实世界看作由各种对象组成，每个对象都具有不同的属性和行为，并且可以与其他对象进行交互。

二、面向对象程序设计的三大特征。

1. 封装（Encapsulation）。

封装是指将数据和操作数据的方法进行封装，构成一个类。

通过对外提供公共的方法和属性，类的内部实现可以隐藏起来，保证类的安全性和可维护性。

2. 继承（Inheritance）。

继承是指子类可以继承父类的属性和方法，并且可以在此基础上进行扩展。

这样可以提高代码的复用性和可维护性，同时也有助于层次化设计。

3. 多态（Polymorphism）。

多态是指同一个类的对象可以呈现不同的形态。

多态的实现是通过继承和接口实现的。

多态可以提高代码的灵活性和可扩展性。

三、面向对象程序设计的基本要素。

1. 类（Class）。

类是面向对象程序设计的基本组成单位，是一种抽象数据类型。

类的属性和方法决定了对象的特征和行为。

2. 对象（Object）。

对象是类的实例，每个对象都有自己的属性和方法，可以与其他对象进行交互。

3. 属性和方法（Property and Method）。

属性和方法是类的两个基本元素，属性是对象的特征或状态，方法是对象具有的行为或动作。

4. 继承（Inheritance）。

继承是一种代码复用的方式，子类可以继承父类的属性和方法，并且可以在此基础上进行扩展。

继承可以实现代码的层次化设计。

5. 重载（Overload）和重写（Override）。

重载是指在一个类中定义多个同名方法，但是参数类型、个数或顺序等不同，以提供更多的操作方式。

重写是指子类重写父类的方法，可以实现多态的功能。

6. 接口（Interface）。

接口是一种规范，规定了类必须实现的一组方法。

它可以实现多态和代码的松耦合。

四、面向对象程序设计的思想和技术。