What is Pascal?

Pascal is a general-purpose high-level programming language for computers. It was designed and founded by Swiss Professor Niklaus Wirth in the late 1960s. The Pascal language named after the French mathematician has now become one of the most widely used DOS-based languages. Its main features are: strict structured form; rich and complete data types; high operating efficiency; and strong error checking ability. Because of the above characteristics, Pascal language can be easily used to describe various algorithms and data structures. Especially for beginners in programming, Pascal language is helpful in cultivating good programming styles and habits. IOI (International Olympiad in Informatics) regards Pascal language as one of the three programming languages. NOI (National Olympiad in Informatics) regards Pascal language as the only programming language promoted. Pascal language is often used as a programming language in universities. A teaching language for learning data structures and algorithms. In the more than thirty years since Pascal came out, various versions suitable for different models have been produced. The one with the greatest impact is the TurboPascal series of software. It is a Pascal compilation system suitable for microcomputers designed and developed by the American Borland Company. The compilation system has developed from version 1.0 launched in 1983 to version 7.0 launched in 1992. Its versions have been continuously updated and its functions have become more complete. Listed below are the main features of TurboPascal Chronicles publication year version name 1983 TurboPascal1.0 TurboPascal2.0 Turbo-87Pascal improves the speed of real number operations and expands the value range 1985TurboPascal3.0 increases graphics capabilities TurboBCDPascal is particularly suitable for commercial applications 1987TurboPascal4.0 provides an integrated development environment (IDE ), introducing the unit concept 1988 Turbo Pascal 5.0 adds debugging function 1989 Turbo Pascal 5.5 supports object-oriented programming (OPP) 1990 Turbo Pascal 6.0 provides object-oriented application framework and library (TurboVision) 1992 Turbo Pascal 7.0 object-oriented application system, more complete IDE TurboVision2.0 1993BorlandPascal7.0 developed ObjectWindows library, __(ForWindows) to provide support for OLE multimedia application development 1995Delphi(ObjectPascal) VisualPascal FreePascal TurboPascal language is a compiled programming language, which provides an integrated environment working system that integrates editing, compilation , running, debugging and other functions in one PS: In the development process of high-level languages, Pascal is an important milestone. The Pascal language was the first language to systematically embody the concepts of structured programming defined by E.W. Dijkstra and C.A.R. Hoare. In 1971, Professor Nicklaus Wirth of the Swiss Federal Institute of Technology invented another simple and clear computer language, which is the Pascal language named after the computer pioneer Pascal. The Pascal language has rigorous syntax, clear layers, easy to write programs, and strong readability. It is the first structured programming language. It was widely welcomed as soon as it was born and spread quickly from Europe to the United States. Walls also wrote a large number of books on programming, algorithms and data structures throughout his life, for which he won the 1984 Turing Award.

There are 5 main versions of Pascal, namely UnextendedPascal, ExtendedPascal, Object-OrientedExtensionstoPascal, BorlandPascal and DelphiObjectPascal. Among them, UnextendedPascal, ExtendedPascal and Object-OrientedExtensionstoPascal were created and maintained by the Pascal Standard Committee. UnextendedPascal is similar to the Pascal user manual and report jointly published by Swiss Professor Niklaus Wirth and K. Jensen in 1974, and ExtendedPascal is based on it. It has been extended and added many new features, all of which belong to the official Pascal standard; Object-OrientedExtensionstoPascal is a technical report published by the Pascal Standards Committee, which adds some features to support object-oriented programming based on ExtendedPascal. feature, but it is an informal standard. Borland Pascal and DelphiObject Pascal are Pascal languages ??designed specifically for compilation tools developed by Borland. The former is a traditional high-level language for the TurboPascal series for DOS and TurboPascal for Windows 3.x, and the latter is Delphi for Windows and Kylix for Linux. Object-oriented programming languages, none of them are formal Pascal standards and are proprietary. However, due to the powerful functions and popularity of the TurboPascal series and Delphi, BorlandPascal and DelphiObjectPascal have become a standard and are familiar to many people. At this point, you may find that my answer is different from what you originally thought. You may have wanted to ask how many versions of Turbo Pascal there are, but I answered how many versions of Pascal language there are. This is a common misunderstanding among beginners: Pascal is a programming tool. In fact, Pascal is the name of a programming language (in a general sense, Pascal can also refer to a person's name. It was originally named to commemorate the famous French philosopher and mathematician Blaise Pascal in the seventeenth century), not programming. tool. I just answered this question purely literally. "Standard Pascal's packed character array cannot be used in TurboPascal! TurboPascal also has its own syntax rules for creating files! assign!!!" Pascal is a programming language, and TurboPascal/FreePascal is the compilation system of Pascal programs. Edited with Pascal The program can run in TurboPascal/FreePascal. Pascal is just a language, and TurboPascal/FreePascal is a compiler. The two cannot be compared. You can compare the two languages ??together, or compare the two compilers together. Compilers are all language-based, so there is no compiler that cannot adapt to the language. In China's Informatics Olympiad, the Pascal programming tool that was more commonly used in the past was TurboPascal.

TurboPascal is a 16-bit programming tool under DOS. Before the emergence of Delphi, it was the most popular Pascal programming tool in the world. It has an advanced compiler with extremely fast compilation speed and a powerful yet easy-to-use integrated development environment. (IDE) is widely popular among microcomputer programmers. It was its emergence that laid the unshakable foundation of Pascal on the DOS/Windows platform. Common versions now include TurboPascal5.5, TurboPascal6.0 and Borland TurboPascalwithObjects7.0. Compared with TurboPascal5.5, TurboPascal6.0 is mainly because the IDE is more powerful, and its programming functions have not changed much. It only adds some new functions, such as the ability to embed asm assembly statements. Borland Turbo Pascal with Objects 7.0 (referred to as Borland Pascal 7.0) has made a new leap. First, the IDE has been further strengthened and provided with a program browser. Then, the programming functions have been greatly improved, and some very useful standard subscripts have been added. The program supports relatively complete object-oriented programming functions, and provides three program compilation modes: DOS real mode, DOS protected mode and Windows mode. It can write protected mode applications that can use expanded memory (XMS) or run on Windows 3. Windows programs running under x also provide an object window library (OWL), which can be used to quickly develop applications with a consistent window interface (DOS or Windows 3.x). Borland Pascal 7.0 was launched in 1992 and was the last version of the Turbo Pascal series under DOS. Now, as TurboPascal is gradually being phased out, the National Informatics Olympiad Finals (NOI) and the International Informatics Olympiad (IOI) have designated FreePascal as the Pascal programming tool used in the competition. FreePascal is a 32-bit Pascal programming tool developed by an international organization. It is a free software and can be used in various operating systems. Depending on the compilation options, it can use Borland Pascal compatible syntax, Delphi2Object Pascal syntax or other syntax to write programs. Because it has a 32-bit compiler and is constantly being updated and developed, it is more powerful than Borland Pascal and has many modern programming features, but it is also very immature and has many loopholes. FreePascal is in the early stages of development, and there are very few corresponding function libraries. Its appeal to programmers is far less than that of Delphi and Kylix, which have VCL and CLX. Basic symbols and reserved words in Pascal: Pascal language can only use the following types of basic symbols: (1) Upper and lower case English letters ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz (2) Numbers 1234567890 (3) Other symbols -*/=lt; gt; lt; =gt ;=lt;gt;()[]{}:=,.;:..' Note that Pascal language is not allowed to use any other symbols except the characters specified above. Supplementary explanation of FreePascal (FP): FreePascal is a product under multiple versions of Pascal and Delphi. The currently more mature version is version 1.0.10 released by FreePascal.org. Since it is a revised version of Pascal, it has been added to FP. There are many things that did not exist before, such as: FillChar series memory block assignment statements, using Power instead of ** (power), but ** can still be used.

In addition, FP has strengthened its mutual compatibility with memory and increased its support for memory. The memory limit in FP is nearly tens of thousands times that of TP and BP. FP also further strengthens unit support, object-oriented programming support, graphics card (sound card) support, graphics advanced coverage support, Windows\Linux\OS/2\.. and many other systems. In the more stable version of FP, you can easily use the Win32 compilation mode to compile Windows applications, which are equivalent to the functions of Delphi. At the same time, in-depth support for dynamic link libraries, controls, databases, files, networks, and OpenGL makes FP stand out. What's more worth mentioning is that FP supports some languages ????of Delphi and C. For example, CStyle language such as A =2 is perfectly supported in FP. FP supports unary and binocular operators, that is, symbols of all versions of Pascal and special symbols such as "@". FreePascal.org is currently revising the FP2.0 version, but it is not as easy to use as 1.0.10, and the stability has also dropped a lot. As of the beginning of 2009, the version has reached 2.2.4. FP is now a recommended tool for competitions [Edit this paragraph] Pascal textbook Section 1 Characteristics of Pascal Language The Informatics Olympiad is an intellectual competition, and its core is to test the contestants' abilities. Intelligence and the ability to use computer programming to solve problems. The Informatics Olympiad requires contestants to have the following abilities: construct mathematical models according to the requirements in the competition questions, construct effective algorithms and select corresponding data structures, write high-level language programs, and pass computer debugging. Programming is the basic skill of the Informatics Olympiad. Therefore, the first step for young people to participate in the competition is to master a high-level language and its programming methods. The Pascal language, named in honor of the French mathematician, is one of the most widely used high-level computer languages ??and is internationally recognized as a model for programming teaching languages. Its main features are: strict structured form; rich and complete data types; high operating efficiency; strong error checking ability. Because of these characteristics, the Pascal language can be easily used to describe various data structures and algorithms and write high-quality programs. Especially for young beginners in programming, Pascal language is conducive to smooth entry and the cultivation of good programming style and habits from the beginning. More and more schools of all types regard Pascal language as the first choice in programming teaching. language. IOI (International Olympiad in Informatics) stipulates Pascal language as one of the two programming languages, NOI (National Olympiad in Informatics) stipulates Pascal language as the only programming language promoted, and NOIp (National Olympiad in Informatics) Make Pascal the most important programming language. There are many versions of the Pascal language. Turbo Pascal 7.0 (or Borland Pacsal 7.0) used in this textbook is currently the most efficient Pascal used on PCs and is the highest version so far in the DOS environment. The hardware environment required for TurboPascal7.0 is any type of PC, and only requires a 1.44M floppy disk drive (of course there are other conditions that are better); the minimum software system includes Turbo.exe (integrated environment) and Turbo.tpl (standard Unit library) two files, it will be more conducive to learning if Turbo.hlp (help file) is included. TurboPascal7.0 can work under DOS operating system or Windows operating system environment. Lesson 1 Pascal language knowledge 1. Overview of Pascal language Pascal language is an algorithmic language. It was designed by Professor Wirth of the Swiss Federal Institute of Technology in Zurich in 1968 and officially published in 1971. The Pascal language was developed on the basis of ALGOL60. It is a structured programming language. It has powerful functions and simple compilation procedures. It was the most influential algorithm language in the 1970s.

From a user's perspective, the Pascal language has the following main features: 1. Structured Pascal can easily write structured programs. This ensures the correctness and readability of the program. In terms of structure, it is better than other algorithmic languages. ⒉ Rich data types Pascal provides integers, real types, character types, Boolean types, enumeration types, subboundary types, and array types, collection types, record types, and file types composed of the above types. In addition, pointer types are provided that are not found in many other languages. The rich data structure and the above-mentioned structural properties allow Pascal to be easily used to describe complex algorithms. ⒊Good applicability: It is suitable for both numerical operations and non-numerical operations. Some languages ??are suitable only for numerical calculations, while others are suitable for commercial data processing and management fields. Pascal has strong functions and can be widely used in various fields. ⒋Writing is freer. Unlike some algorithmic languages, there are no strict regulations on the writing format of the program. Pascal allows multiple statements to be written on one line, and a statement can be written on multiple lines. This allows Pascal programs to be written as gracefully as poetry and easy to read. Due to the above characteristics, many schools choose Pascal as a major language in programming courses. It can give students rigorous and good basic training in programming. Develop students' structured programming style.