Computer programming

Computer programming  (often shortened to  programming  ) is a process that leads from an original formulation of a computing problem to executable computer programs . Programming Involves activities Such As analysis, Developing understanding, Generating algorithms , verification of requirements of algorithms Including Their correctness and resources consumption, and implementation (Commonly Referred to as  coding  [1]  [2]  ) of algorithms in a target programming language . Source codeis written in one or more programming languages. The purpose of programming is to find a sequence of instructions that will automate a specific task or problem solving solution. The process of programming thus requires a variety of expertise, including knowledge of the application domain , specialized algorithms, and formal logic .

Related tasks include testing , debugging , and Maintaining the source code , implementation of the build system, and management of artifacts derived Such As machine code of computer programs. These might be regarded share of the programming process, aim Often the term  software development  is used for this larger process with the term  programming  ,  implementation  , or  coding  reserved for the actual writing of source code. Software engineering combined engineering techniques with software development practices.

History

See also: History of programming languages
Ada Lovelace , whose notes were added to the end of Luigi Menabrea’spaper included the first algorithm for Analytical Engine . She is often recognized as a first computer programmer.

Programmable devices have existed at least as far back as 1206 AD, when the automata of Al-Jazari were programmable, via pegs and cams , to play various rhythms and drum patterns;  [3] and the 1801 Jacquard loom could produce entirely different weaves by changing the “program” – a series of pasteboard cards with holes punched in them.

HOWEVER, the first computer program is Generally dated to 1843. When mathematician Ada Lovelace published an algorithm to calculate a sequence of Bernoulli numbers , Intended to be the carried out by Charles Babbage ‘s Analytical Engine .  [4]

Data and instructions were once stored on external punched cards, which were kept in order and arranged in program decks.

In the 1880s Herman Hollerith invented the concept of storing  data  in machine-readable form.  [5]  Later a control panel (plugboard) added à son 1906 Type I Tabulator allowed it to be programmed for different jobs, and by the late 1940s, unit record equipment Such as the IBM 602 and IBM 604 , Were programmed by control panels in a similar way; have been the first electronic computers . However, with the concept of the stored-program computers introduced in 1949, both programs and data were stored in the same way in computer memory .

The  neutrality of this article is disputed  . Relevant discussion can be found on the talk page . Please do not remove this message until conditions are met .  (December 2017)  ( Learn how to remove this template message )
This section  needs additional quotes for verification  . Please help to improve this article by adding quotations to reliable sources . Unsourced material can be challenged and removed.  (December 2017)  ( Learn how to remove this template message )

Women had a crucial role in computer programming from the beginning, the first computer programmers were women [quotation needed]. Computer programming was considered low-skilled and was low-waged, much assumed the coding process was trivial and mechanical, work that could be given to women. Soon, female coders became involved with the intellectual processes which was originally done by the male planners. In the 1960s, computer companies, like IBM , started to make low-cost computers. While these computers could be mass-produced, the software systems could not. Companies became in need of programmers, who had to solve varied and complex problems. This is a new appreciation for programmers, which is more important for their programs than this.  [6]

Machine code was the language of early programs, written in the set of the particular machine, often in binary notation. These languages were written in a text format, (eg, ADD X, TOTAL), with abbreviations for each operation and meaningful names for specifying addresses. HOWEVER, Because an assembly language is little more than a different notation for a Machine language, any two machine with different instruction sets also have different assembly languages.

High-level languages allow the program to write programs in terms That are more abstract , and less bound to the Underlying hardware. They allow the power of computers to make programming easier  [7]  by allowing programmers to specify calculations by entering a formula directly (eg, Y = X * 2 + 5 * X + 9 ). FORTRAN , the first widely used high-level language to have a functional implementation, came out in 1957  [8]  and many other languages ​​were soon developed – in particular, COBOL aims at commercial data processing, and Lisp for computer research.

Programs were mostly still entered using punched cards or paper tape . See computer programming in the punch card era . By the late 1960s, data storage devices and computer terminalsbecame inexpensive enough that they could be created by typing directly into the computers. Text editors have been made easier than ever before.

Modern programming

Quality requirements

Whatever the approach to development may be, the final program must satisfy some fundamental properties. The following properties are among the most important:

  • Reliability : how often the results of a program are correct. This depends on conceptual correctness of algorithms, and minimization of programming errors, such as mistakes in resource management (eg, buffer overflows and race conditions ) and logic errors (such as division by zero goldoff-by-one errors).
  • Robustness : how well do you have problems with problems (not bugs)? This includes situations such as incorrect, inappropriate or corrupt data, unavailability of such resources, operating system services and network connections, user error, and unexpected power outages.
  • Usability : the ergonomics of a program: the ease with which it is used for the purpose of its intended purpose or in some cases even unanticipated purposes. Such issues can make or break its success even regardless of other issues. This involves a wide range of textual, graphical and sometimes hardware elements that improve the clarity, intuitiveness, cohesiveness and completeness of a program’s user interface.
  • Portability : the range of computer hardware and operating systems platforms on which the source code can be compiled / interpreted and run. This document is a preview generated by EVS Page 5
  • Maintainability : the ease with which a program can be modified by its present or future developers in order to make improvements or customizations, or fix bugs and security holes , or adapt it to new environments. Good practices  [9]  during initial development make the difference in this look. This quality can not be directly related to the end user but it can significantly affect the fate of a program over the long term.
  • Efficiency / performance : Measure of system resources a program consumes (processor time, memory space, slow devices such as disks, network bandwidth and to some extent user interaction): the less, the better. This also includes careful management of resources, for example cleaning up temporary files and eliminating memory leaks .

Readability of source code

In computer programming, readability refers to the ease with which a human reader can understand the purpose, control flow , and operation of source code. It affects the aspects of quality above, including portability, usability and most importantly maintainability.

Readability is important because they spend the majority of their time reading, trying to understand and modifying existing source code, rather than writing new source code. Unreadable code often leads to bugs, inefficiencies, and duplicated code . A study  [10]  found that a few simple readability transformations made the code shorter and drastically reduced the time to understand it.

Following a consistent programming style often helps readability. However, readability is more than just programming style. Many factors, having little or nothing to do with the ability of the computer to efficiently compile and execute the code, contribute to readability.  [11]  Some of these factors include:

  • Different indent styles (whitespace)
  • Comments
  • Decomposition
  • Naming conventions for objects (such as variables, classes, procedures, etc.)

The presentation aspects of this (such as indents, line breaks, color highlighting, and so on) are often handled by the source code editor , but the content aspects of the program’s talent and skills.

Various visual programming languages have also been developed with the intention to resolve readability concerns by adopting non-traditional approaches to code structure and display. Integrated development environments(IDEs). Techniques like Code refactoring can enhance readability.

Algorithmic complexity

The academic field and the engineering practice of computer programming are both largely concerned with discovering and implementing the most efficient algorithms for a given class of problem. For this purpose, algorithms are classified into  orders  using so-called Big O notation , which expresses resource use, such as execution time or memory consumption, in terms of the size of an input. Expert programmers are familiar with a variety of well-established algorithms and their respective complexities and uses this knowledge to choose algorithms that are best suited to the circumstances.

Methodologies

The first step in most formal software development processes is required analysis, followed by testing to determine value modeling, implementation, and failure elimination (debugging). There is a lot of different approaches for each of these tasks. One of the most popular methods of analysis is Use Case analysis. Many programmers use forms of agile software development where the various stages of formal development are more integrated together. There are many approaches to the Software Development Process.

Popular modeling techniques include Object-Oriented Analysis and Design ( OOAD ) and Model-Driven Architecture ( MDA ). The Unified Modeling Language ( UML ) is a notation used for both OOAD and MDA.

A similar technique is used for database design is Entity-Relationship Modeling ( ER Modeling ).

Technical implementation include imperative languages ( object-oriented or procedural ), functional languages , and logic languages .

Measuring language usage

Main article: Measuring programming language popularity

It is very difficult to determine what are the most popular of modern programming languages. Methods of measuring the language of the application of the language of the language,  [12]  the number of books and the teaching of the language of code written in the language (this underestimates the number of users of COBOL).

Some languages ​​are very popular for particular types of applications, while some languages ​​are regularly used. For example, COBOL is still very strong in corporate data centers  [13]  often on large mainframe computers , Fortranin engineering applications, scripting languages in Web development, and C in embedded software . Many applications use a mix of several languages ​​in their construction and use. New languages ​​are designed around the syntax of a new language added, (for example C ++adds object-orientation to C, and Java adds memory management and bytecode to C ++, but as a result, loses efficiency and the ability for low-level manipulation).

Debugging

Debugging is a very important task in the software development process since having defects in a program can have significant consequences for its users. Some languages ​​are more prone to some types of faults because their specifications do not require. Use of a static code analysis tool can help you detect some possible problems. Normally the first step in debugging is to attempt to reproduce the problem. This can be a non-trivial task, for example with parallel processes or some unusual software bugs. Also, specific user’s environment and usage history can make it difficult to reproduce the problem.

After the bug is reproduced, the input of the program can be simplified to make it easier to debug. For example, a bug in a compiler can make it crash when parsing some large source file. However, after simplification of the test case, only few lines from the original source file can be sufficient to reproduce the same crash. Such simplification can be done manually, using a divide-and-conquer approach. The program will try to remove some parts of the original test case and check if the problem still exists. When debugging the problem in a GUI, the program will try to make the most of the problem.

Debugging is often done with IDEs like Eclipse , Visual Studio , Xcode , Kdevelop , NetBeans, and Code :: Blocks . Standalone debuggers like GDB are also used, and these often provide less of a visual environment, usually using a command line . Some text editors such as Emacs allow GDB to be invoked through them, to provide a visual environment.

Programming languages

Main articles: Programming language and List of languages

Different programming languages ​​support different styles of programming (called  programming paradigms ). The choice of language is subject to several considerations, such as company policy, suitability to task, availability of third-party packages, or individual preference. Ideally, the programming language will be selected. Trade-offs from this ideal in the field of computer programming, the availability of compilers for that language, and the efficiency of which programs in a given language execute. Languages ​​form an approximate spectrum from “low-level” to “high-level”; “low-level” languages ​​are more machine-oriented and faster to execute, whereas “high-level” is more easily and more easily. It is usually easier to code in “high-level” languages ​​than in ”

Allen Downey , in his book  How To Think Like A Computer Scientist  , writes:

The details look different in different languages

  • Input: Gather data from the keyboard, a file, or some other device.
  • Output: Display data on the screen or send data to a file or other device.
  • Arithmetic: Perform basic arithmetical operations like addition and multiplication.
  • Conditional Execution: Check for certain conditions and execute the appropriate sequence of statements.
  • Repetition: Perform some action repeatedly, usually with some variation.

Many computer languages ​​provide a mechanism for call functions provided by shared libraries . Provided the functions in a library follow the appropriate run-time conventions (eg, method of passing arguments ), then these functions can be written in any other language.

Programmers

Main article: Programmer
See also: Software developer and Software engineer

Computer programmers are those who write computer software. Their jobs usually involve:

  • Coding
  • debugging
  • Documentation
  • Integration
  • Maintenance
  • Requirements analysis
  • Software architecture
  • Software testing
  • Specification

See also

  • ACCU
  • Association for Computing Machinery
  • Computer networking
  • Hello world program
  • Institution of Analysts and Programmers
  • National Coding Week
  • System programming
  • The Art of Computer Programming

References

  1. Jump up^   Shaun Bebbington (2014). “What is coding” . Retrieved 2014-03-03 .
  2. Jump up^   Shaun Bebbington (2014). “What is programming” . Retrieved 2014-03-03.
  3. Jump up^   Fowler, Charles B. (October 1967). “The Museum of Music: A History of Mechanical Instruments”.  Music Educators Journal  . Music Educators Journal, Vol. 54, No. 2.  54  (2): 45-49. doi : 10.2307 / 3391092 . JSTOR  3391092 .
  4. Jump up^   Fuegi, J .; Francis, J. (2003). “Lovelace & babbage and the creation of the 1843 ‘notes ‘ “.  IEEE Annals of the History of Computing  .  25  (4): 16.doi : 10.1109 / MAHC.2003.1253887 .
  5. Jump up^  “Columbia University Computing History – Herman Hollerith” . Columbia.edu . Retrieved 2010-04-25 .
  6. Jump up^   Ensmenger, Nathan (2015). “”Beards, Sandals, and Other Signs of Rugged Individualism”: Masculine Culture within the Computing Professions”.  Osiris 30  (1): 38–65. doi:10.1086/682955.
  7. Jump up^  “Fortran creator John Backus dies” .  msnbc.com  . Retrieved 19 November 2014 .
  8. Jump up^  “John Fortran creator Backs dies – Tech and gadgets- msnbc.com” . MSNBC. 2007-03-20 . Retrieved 2010-04-25 .
  9. Jump up^  “Programming 101: Tips to become a good programmer – Wisdom Geek” .  Wisdom Geek  . 2016-05-19 . Retrieved 2016-05-23 .
  10. Jump up^  James L. Elshoff Michael Marcotty,Improving computer program to aid readability modification, Communications of the ACM, v.25 n.8, p.512-521, Aug 1982.
  11. Jump up^   Multiple (wiki). “Readability” .  Docforge  . Retrieved 2010-01-30 .
  12. Jump up^  Survey of Job advertising
  13. Jump up^   Mitchell, Robert. “The Cobol Brain Drain” . Computer World . Retrieved 9 May 2015 .

Leave a Reply

Your email address will not be published. Required fields are marked *

Copyright computerforum.eu 2018
Shale theme by Siteturner