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Programming Languages



Computers can deal with different kinds of problems if they are given the right instructions for what to do. Instructions are first written in one of the high-level languages, e.g. FORTRAN, COBOL, ALCOL, PL/I, PASCAL, BASIC, or C., depending on the type of problem to be solved. A program written in one of these languages is often called a source program, and it cannot be directly processed by the computer until it has been compiled, which means interpreted into machine code. Usually a single instruction written in a high-level language, when transformed into machine code, results in several instructions. Here is a brief description of some of the many high-level languages:

FORTRAN acronym for FORmula TRANslation. This language is used for solving scientific and mathematical problems. It consists of algebraic formulae and English phrases. It was first introduced in the United States in 1954.

COBOL acronym for Common Business-Oriented Language. This language is used for commercial purposes. COBOL deals with problems that do not involve a lot of mathematical calculations. It was first introduced in 1959.

ALGOL acronym for Algorithmic Language. Originally called IAL which means International Algebraic Language. It is used for mathematical and scientific purposes. ALGOL was first introduced in Europe in 1960.

PL/IProgramming language I. Developed in 1964 to combine features of COBOL and ALGOL. Consequently, it is used for data processing as well as scientific applications.

BASIC acronym for Beginner’s All-purpose Symbolic Instruction Code. Developed in 1965 at Dartmouth College in the United States for use by students who require a simple language to begin programming.

C developed in the 1970s to support the UNIX operating system. C is a highly portable general-purpose language. C was designed to be a language that would be suitable for writing system's software, like the core parts of an operating system. The code generated by the compiler had to be very efficient if the language was to be used in this way. Anything a compiler would have difficulties with was dropped. Consequently, in some respects the language is simpler than other Algol family languages that have retained the relatively complex nested program structures. If C was to be used for writing things like "device driver code" (the code that actually interacts with the peripheral controllers), then it had to allow the programmer get down the hardware level and manipulate bits in specific registers and in particular memory addresses. This gives the programmer considerable power, and lots of responsibility.



C++ started as a dialect of C around about 1980, it has been revised twice since then. But they are still very similar languages (in fact, a correct C program should be acceptable to a C++ compiler). The C++ language aimed to achieve three things: to be a better C; to support "abstract data types"; to permit the use of a programming technique known as "object oriented programming" (OOP). C++ was designed to permit more compile time checking and also to offer alternatives to various features of C that were known to be common sources of programming errors.

Other such languages are APL (developed in 1962), PASCAL (named after Blaise Pascal and developed in 1971), and LISP and PROLOG, both of which are used for work in artificial intelligence. LOGO is a development of LISP which has been used to develop computer based training packages.

At a superficial level, programming languages and natural languages are similar. Programming languages have grammatical rules that need to be learnt, just as natural languages do. At the same level, computers can ‘’understand’’ and ‘’communicate with’’ humans through programming languages: superficial interaction is possible. However, programming languages are data-free and therefore contain no information in themselves. The information is contained in the data which is processed, but is independent of the language which is used to write the commands to proceed it. The sole purpose of a programming language is to give instructions to a computer, which - providing they are syntactically correct - will be executed. A syntactically correct statement in a programming language has only one interpretation. By definition, it cannot be ambiguous. You cannot make jokes in computer languages.

Vocabulary Notes

a source program – вхідна, початкова програма

a purpose – мета, ціль; the sole purpose – єдина мета

to support [sq'pLt] – підтримувати, допомагати

a compiler – компілятор, програма-компілятор; compile time – час компіляції, час роботи компілятора; to compile – вибирати інформацію, збирати матеріал, компілювати програму

to retain – тримати, акумулювати, тримати в пам’яті

а peripheral controller – периферійний контролер

considerable – значний, важливий

to revise – перевіряти, виправляти

acceptable [qk'septqbl]– допустимий

superficial ["sju:pq'fIS(q)l]– зовнішній, поверхневий

interaction– взаємодія, взаємозв’язок

syntactically [sIn'txktIklI]– синтаксично

ambiguous [xm'bIgjuqs] – двозначний, сумнівний

to make jokes – шуткувати

to deal with– мати справу з

to depend on– залежити від

a source –джерело

to process['preuses] обробляти

brief[brJf] короткий

a description– опис

to introduce– вводити, представляти

consequently['kOnsIkwqntlI]– отже, отож

nested structure ['strAktSq] – гніздова (вкладена структура)

Comprehension





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