Text B. PROGRAMMING

A Program is a set of instructions written in a programming language and designed to make a computer perform a series of specified tasks that solve a particular problem or achieve a specific goal. Programming is the act of designing and writing programs in a development cycle that has five processes: problem definition, algorithm development, coding, program testing and debugging, and documentation.

In defining the problem, programmers meet with users to identify the output desired and other expectations for a program; they also determine the input and machinery to be used. The programmer constructs the algorithm –the prescribed set of well-defined rules or processes for the solution of the problem – that describes the program's process from start to finish, including the logic structures used. The algorithm can be written in pseudocode or drawn as a flowchart. Programmers use a structured programming approach, building the program in modules in a top-down manner; structure charts show the relationships among the program modules.

The algorithm is coded (translated into statements) in a programming language whose choice is sometimes crucial to the success of the program. Once written out, the program is tested to find bugs, or errors in the syntax or logic. Program testing and debugging involves desk checking, compilation, running the program with sample data, and field testing.

A program's internal documentation covers the trail of development, including comments within the code to remind the original programmer of (or tell other programmers) the meaning of each line of code and the flow of the program's logic. External documentation is prepared for user manuals; on-line documentation supports users while they use the program.

Programming languages are classified as first-, second-, third-, fourth-, or fifth -generation languages.) The first generation of languages, machine language, is written in the binary 0 and 1 values the microcomputer can process. The second-generation assembly languages use alphanumeric mnemonic codes to replace machine commands and need an assembler to translate their code to machine language.

The third-generation procedural languages dominate the programming field and require compilers or interpreters to translate their code to machine language. Compilers translate the whole program at once, storing object code in an executable file. Interpreters translate the source code line by line; the computer can run each line as it is translated. Common third -generation languages in use today include BASIC, Pascal, C, COBOL, FORTRAN, Ada, RPG, and LISP.

The fourth-generation problem-oriented languages bring programming more within the reach of nonprogrammers, starting with object-oriented programming, then the use of application generators and authoring systems, on to the use of HyperTalk, and finally to query and scripting languages.

The fifth-generation natural languages do not produce code but follow human language grammar rules. They are not yet well developed.

Task 9. Give the description (in writing) of programming methods and software design.

SUPPLEMENTARY READING

WEBPAGE CREATOR

Webpages are documents designed for use on the World Wide Web which is an Internet service that allows users to view linked webpages stored on Web server computers. A set of related documents stored on a Web server is known as a website and the starting webpage of a website is referred to as the homepage. Webpages are viewed using a program called a browser.

Many websites deal with a particular area of interest or topic and almost every topic imaginable is dealt with by some website. Special websites known as search engines allow users to find websites related to a particular topic by searching a database (a type of applications program used for storing information so that it can be easily searched and sorted) of links to other websites. Some websites allow users to download files (copy files from a server computer to a client computer). Files available for downloading include applications programs that allow the user to perform specific tasks such as wordprocessing, upgrades to programs that add features or fix bugs (faults in the program), software drivers (programs that are used to control peripheral devices such as printers), development tools (software that can be used for writing programs or creating material such as webpages). Downloadable programs that are free to download and use are known as freeware. Programs that are free to download and try but should be paid for if the user wishes to continue to use them, are known as shareware.

Websites can be created by anyone who has the necessary programs and equipment. When the website creator creates their website, they publish it (copy it to a Web server computer). This is referred to in the text as 'putting up a site'. Every website has a Web address that takes the user to the first page of the website i.e. the homepage. The Web address usually starts with 'www' and ends with 'com' if it is a company (co.uk is used for a company in the United Kingdom). The parts of the Web address are separated by dots (.) e.g. www.themovieshrine.com but there is no dot at the end of the address. The domain name is the part of the Web address that indicates what network the website is stored on. Sometimes the Web address used is not the actual address of the website. When the address is typed into a browser program, the browser is automatically re-directed to the actual web address. This is usually done by an ISP (Internet service provider - an organisation that provides Internet connections for a fee) to make the Web address look as if it is owned by a private company.

Webpages are created by adding HTML (hypertext markup language) tags to plain text to determine the way that the webpage will be displayed in a browser program and to create hyperlinks (dynamic links that the user clicks on to display other webpages). Webpages can be created using a very basic worprocessor program known as a text editor, but special programs are available that allow the user to create webpages without knowing about HTML e.g. Netscape Composer. This program is part of a package of programs for managing websites called Netscape Communicator. A website owner can register their website on a search engine. This means that they submit their Web address and details of their website to be included in the search engine database i.e. to be listed on the search engine. One of the best known search engine websites is called Yahoo. As well as providing a search engine, websites such as Yahoo provide a variety of facilities including enabling users to form newsgroup clubs that discuss various topics using email. After a website has been created and published, it is important that the creator updates the webpages frequently to vary and improve the website, keep the information up to date and make sure that the hyperlinks still connect to existing websites. A static site is a website that does not change its content. It is common for an email address to be provided on the website to allow users to contact the website creator to provide feedback about the website. Creating a professional website involves more than just publishing webpages. The website needs to be planned carefully if it is to be a success. This involves a number of stages including analysing the demand and other related websites, designing the webpages and the overall structure of the website, publishing and advertising the website including registering it on search engines and getting other websites to create links to it, and evaluating the website after it has been published by using user feedback and statistics on the use of the website.

Date: 2015-01-02; view: 1559