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This article mainly introduces the process of the development of programming language in the computer network, which is very detailed and has a certain reference value. Interested friends must read it!

The development of programming language has gone through four processes: machine language, assembly language, high-level language and non-procedural language. From the perspective of development, programming languages can be divided into four generations: the first generation machine language, the second generation assembly language, the third generation high-level language and the fourth generation non-procedural language.

Programming language is a language used to write computer programs. Language is based on a set of tokens and a set of rules. According to the rules, the whole of a token string made up of tokens is language. In programming languages, these token strings are programs. Programming language has three factors, namely, grammar, semantics and pragmatics. Syntax represents the structure or form of a program, that is, the law of combination between the tokens that make up the language, but does not involve the specific meaning of these tokens or the user. Semantics represent the meaning of the program, that is, the specific meaning of each token expressed in various ways, but does not involve the user.

The development of programming language has experienced four stages: machine language, assembly language, high-level language and non-procedural language.

Since the 1960s, thousands of programming languages have been published in the world, but only a small number of them have been widely used. From the perspective of development, programming languages can be divided into four generations.

First generation machine language

Machine language is composed of binary 0 and 1 code instructions, and different CPU have different instruction systems. Machine language programs are difficult to write, modify and maintain, which requires users to allocate storage space directly, so the programming efficiency is very low. The language has become obsolete.

Second generation assembly language

Assembly language instruction is the symbolization of machine instruction, which has a direct corresponding relationship with machine instruction, so assembly language also has some shortcomings, such as difficult to learn and use, easy to make mistakes, difficult to maintain and so on. However, the assembly language also has its own advantages: it can directly access the system interface, and the machine language programs translated by the assembler are highly efficient. From the perspective of software engineering, assembly language is used only when the high-level language can not meet the design requirements, or does not have the technical performance to support a specific function (such as special input and output).

The third generation high-level language

A high-level language is user-oriented and basically independent of the type and structure of the computer. Its greatest advantage is that it is close to arithmetic language and natural language in form and close to the concept commonly used by people in concept. One command in a high-level language can replace several, dozens or even hundreds of instructions in assembly language. Therefore, the high-level language is easy to learn and use, has strong versatility and is widely used. There are many kinds of high-level languages, which can be further classified from two aspects: the application characteristics and the description of the objective system.

I. Classification from the point of view of application

From the perspective of application, high-level language can be divided into basic language, structured language and special language.

(1) basic language

The basic language is also called the universal language. It has a long history, spread widely, has a large number of developed software libraries, has a large number of users, and is familiar with and accepted by people. FORTRAN, COBOL, BASIC, ALGOL and so on belong to this kind of language. FORTRAN is one of the most popular and earliest high-level languages in the world. Since the 1990s, it has been playing an important role in engineering and scientific computing, and has been welcomed by scientists and technicians. BASIC language is an interactive language developed in the early 1960s to adapt to the time-sharing system, which can be used in general numerical calculation and transaction processing. BASIC language is simple in structure, easy to learn and use, and has the ability of interaction, so it has become an entry-level language for many beginners to learn programming.

(2) structured language

Since the 1970s, the ideas of structured programming and software engineering have been increasingly accepted and appreciated by people. Under their influence, some influential structured languages have emerged. These structured languages directly support structured control structures and have strong process structure and data structure capabilities. PASCAL, C, Ada languages are their outstanding representatives.

PASCAL is the first modern high-level language that systematically embodies the concept of structured programming. The initial goal of software development is to use it as a teaching tool for structured programming. Because of its clear module, complete control structure, rich data types and data structure, strong language expression ability and easy transplantation, it has been chosen as the teaching language by many colleges and universities at home and abroad. and it is widely used in scientific calculation, data processing and system software development.

C language has rich functions, strong expression ability, rich operators and data types, flexible and convenient use, wide application, strong transplant ability, high compilation quality, high target program efficiency, and has the advantages of high-level language. At the same time, C language also has many characteristics of low-level language, such as allowing direct access to physical addresses, bit operations, most of the functions of assembly language, direct operation of hardware, and so on. The quality of the target program produced by compiling programs in C language is comparable to that produced by assembly language, and it has the laudatory name of "portable assembly language". It has become one of the important languages for writing application software, operating system and compiler.

(3) Special language

It is a language specially designed for a special application, usually with a special grammatical form. Generally speaking, the scope of application of this language is narrow, portability and maintainability are not as good as structured programming languages. With the development of time, hundreds of professional languages have been used, including APL language, Forth language and LISP language.

Second, from the description and classification of objective system

From the perspective of describing objective systems, programming languages can be divided into process-oriented languages and object-oriented languages.

(1) process-oriented language

The programming language composed of "data structure + algorithm" programming paradigm is called process-oriented language. Most of the programming languages introduced above are process-oriented languages.

(2) object-oriented language

The programming language composed of "object + message" programming paradigm is called object-oriented language. The popular object-oriented languages are Delphi, Visual Basic, Java, C++ and so on.

Delphi language has a visual development environment and provides object-oriented programming methods. It can design all kinds of applications with Windows lattices (such as database application systems, communication software and 3D virtual reality, etc.), and can also develop multimedia application systems.

Visual Basic language, referred to as VB, is a development environment and tool for developing applications. It has a good graphical user interface and adopts a new object-oriented and event-driven mechanism to integrate process and structured programming. Its graphical conception in application development makes it easy to create an application interface without writing any program, and it is very similar or even consistent with the Windows interface.

Java is an object-oriented programming language that does not depend on a specific platform. It is simple, reliable, compilable, extensible, multithreaded, structurally neutral, type display specification, dynamic storage management, and easy to understand. It is an ideal programming language for developing Internet application software.

The fourth generation of non-procedural language

4GL is a non-procedural language, coding only need to explain "what to do", do not need to describe the details of the algorithm.

Database query and application generator are two typical applications of 4GL. Users can use database query language (SQL) to perform complex operations on the information in the database. Users only need to tell SQL,SQL that the search process will be completed automatically, such as where the content to be searched is, and according to what root conditions to search. The application generator is a high-level language program that is "automatically generated" to meet the needs of users. It should be said that the real fourth-generation programming language has not yet appeared. The so-called fourth generation language mostly refers to the software tool products with 4GL characteristics based on a certain language environment, such as System Z, such as PowerBuilder, FOCUS and so on. The fourth generation programming language is an application-oriented programming language designed for end-users. It has the advantages of shortening the application development process, reducing the maintenance cost, minimizing the problems in the debugging process and being user-friendly.

These are all the contents of this article entitled "which processes have been experienced in the development of programming languages in computer networks?" Thank you for reading! Hope to share the content to help you, more related knowledge, welcome to follow the industry information channel!

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