Computer languages

A set of instructions described in a certain way forms a computer language. There are about a dozen common computer languages. Each language has its strong points and its drawbacks. Now the more complicated the language, the nearer it should be to human thought process, and the easier for us to get the computer to do what we want. The lower the level, the nearer the language is to the way that the computer operates (by instructions represented as binary numbers). So low-level are machine code and assembly language. The machine code is the simple on/off, yes/no situation of electrical power which is built upon technical instructions (software).

Assembly language is a system of letters devised at the machine code level. These letters are easier to remember than numbers. One of the advantages of both machine code and assembly language is that they help you to understand the inner processes of the computer, i.e. how information moves around inside the computer. Machine code (or assembly language) is used if speed is important. Then the computer responds to the stimulus at once. An example of this might be traffic control. Another example is the use of a computer to control a nuclear power station. Here an accident can happen if action is not taken quickly in response to some stimulus representing a dangerous condition.

The point of high-level languages is to come near to the human brain, in order to try to make low the probability of error. The central point here is structured programming. What is meant by structured programming? It means developing a programme in separate sections, building blocks ("editing" the data). These blocks can then be joined together and structured into a whole.

Readability is an important characteristic of a programming language. Some languages, like BASIC, are rather easy to write, but not all that easy to read. By read we mean sit down with the programme listing and try to understand what the programme is doing.

Attempts are made to standardize languages in order to make them transportable - to make it possible to run them on different machines. So transportability is another important characteristic of a language. The worst language in this respect is BASIC, which exists in a very great number of variants. The advantage of some languages is that they have file-handling facilities built in them. If they do not, the programme cannot be so easily moved from one system to another.

High-level languages are also different in respect to arithmetical precision - each of them provides a different degree of precision.

Still another characteristic is speed at run time. The user has to find out what different languages have to offer and choose the one that fits his needs.

- FORTRAN (FORmulaTRANslator) is one of the oldest computer languages. It was developed for scientific work only, but now it is widely used by mathematicians. Therefore anyone planning to work at a research institute with computers would do well to learn it.

BASIC (Beginners' All-purpose Symbolic Instruction Code) is a programming language that is more widely used than any other. It was developed as a tool for teaching computer programming. BASIC is similar to FORTRAN in many ways, but is much easier to use. It is based on English-like instructions and writing programmes is easy in BASIC. That is why it is so popular.

PASCAL is the newer high-level programming language. It was developed as a tool for teaching the basics of structural programming and today it has powerful techniques for structuring data PASCAL is considered to be good for microcomputers. Though it is more complicated to learn than BASIC, in recent years PASCAL has become very popular for writing business and scientific programmes. As a result, PASCAL has developed into a powerful general-purpose language. It is a good educational tool, it is strong on readability, strong on transportability, it has in-built file-handling techniques and is fast at run time.

ALGOL (ALGOrithmic Language), sometimes given as ALGebraic Oriented Language, is also one of the oldest universal computer languages It was developed in 1958 and adapted in I960. ALGOL is similar to FORI RAN but with several important advantages. ALGOL-68 is not unlike PASCAL. It reads rather similarly, though slightly less easily, has good data structures and is in common use, mostly as a scientific language ALGOL is used more in Europe than in the US.

COBOL (COmmon Business Oriented Language) is the most popular computer language for business use. As COBOL is based on everyday English, people can read and understand programmes, even if they know nothing about data processing, which is a great advantage.

COBOL has good file-handling techniques and data structures that can be used for different purposes. There is an international standard which provides for transportability: a programme designed for one computer may be run on another with minimal changes. Some people forecast that COBOL will soon be used widely on micros - when the programmers who work with minicomputers understand clearly the power of the micro and when programmers at present using BASIC on micros see its negative points.

There are a number of other less well-known, but not less good languages. Among these are LISP, CORAL, STOIC, FORTH, PILOT and others.

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