Basically there are two main types of computer programming languages, High level languages and Low level languages. Assembly language and machine language are the examples of low level language and C ++, BASIC, FORTRAN, JAVA etc are examples of high level languages.
Introduction to Programming Languages
Computer can perform various tasks depending upon the requirements of the
User. In order to perform these tasks, computers need instructions which tell them
How to execute the required task. The set of instructions (executed by the CPU) to solve
Particular problem is called computer program (or simply program)
A programming language defines a format for writing instructions in a
Specific order, which are to be executed by a computer. Programming languages also
Provide a framework for expressing algorithms. Programming languages are a way of
Communicating with the computer. The actual details of how programming concepts work are not so simple however, we will discuss them briefly
Types of computer languages
There are many different computers available for writing programs. Each has its strength and weakness and must be assessed based upon need. A language that is particularly well suited for one application may not work for another.
There are two types of computer languages
- Low level computer
- High level computer
Low level language
Low level languages provide the programmer with a high degree of control, but they require a detailed knowledge of the hardware to be used. They are really only required for advanced programming needs. There are two main types of low level language.
- Machine language
- Assembly language
The processor within a computer can perform various operations, each of which is identified within an operation code (or code). It is possible to write a program directly in machine code by using the correct opcodes in the correct sequence into memory, along-with the required data values and para-metes values. The program could be depicted as a series of binary numbers. This however is not a very practical way to write a program. Apart from being complex and time-consuming. Programs written in this way would tend to be error prone and would be very difficult to debug. For this reason, programs are generally written in a language which is easier for humans to understand and can also be translated into machine code for the processor to understand.
Assembly language is very close to machine language. The commands are represented in assembly language by short names called memories (pronounced Ne-Monica). For example d means load accumulator with a particular data value. Because each type of processor has a different set of operations, different processors
Use different Assembly languages. Assembly language programming is complex but
It provides a much higher degree of control than high level languages, Programs
Written in Assembly Language code are translated into machine code by an
assembler. Machine code can also be converted back into assembly code using a
High LEVEL LANGUAGES
High level languages are close to human languages and far from the machine
Language. These are machine independent languages which are also known as “third
Generation” languages. These languages consist of English words, basic mathematical
Symbols and a few punctuation characters. These languages allow simple statements
To be expressed concisely. Each high level language has its own language translator history of some of the major programming language is given bellow.
- FORTRAN (FORmu1a TRANs1ation)
In 1957, FORTRAN appeared as the first major high level languages appeared
In the form of FORTRAN. FORTRAN stands for Formula Translation. The
Language was designed at IBM for scientific computing. It was mainly used
For scientific purposes.
BASIC (Beginners All-purpose Symbolic Instruction Code)
BASIC was designed to allow students to write programs using time-sharing
Computer terminals. BASIC was intended for easy learning programming
Concepts. The design principles of BASIC were:
- Be easy for beginners to use.
- Be a general-purpose language.
- Allow advanced features to be added for experts (while keeping the
Language simple for beginners).
- Be interactive.
- Provide clear and friendly error messages.
- 2 Respond fast for small programs.
- Not require an understanding of computer hardware.
- Shield the -user from the operating system.
COBOL (Common Business Oriented Language)
Through FORTRAN was good at handling numbers, it was not so good at
Handling input and output, which mattered most to business computing.
COBOL was designed as the language for businessmen. Its only data types
Numbers and strings of text. A COBOL program consists of four or five
Major sections. COBOL statements also have a very English-like grammar,
Making it quite easy to learnt Because of its simplicity it had been very
Popular among business community.
LISP stands for List Processing language. It was designed for Artificial
Intelligence (Al) research. Because it was designed for such a highly
Specialized field, its syntax (programming rules) was very different from
It has the unique ability to modify itself, and hence grow on its own.
It is being used even today because it is highly specialized.
- —P SCAL (PASCAL is a language named after a Scientist Pascal)
Pascal was designed in a very orderly approach; it combined many of the best
Features of the languages in use at the time, COBOL, FORTRAN, and
ALGOL. While doing so, many of the irregularities of these languages were
Cleaned up, which helped it to gain popularity. The combination of features,
Input/output and solid mathematical features, made it a highly successful
- C and C++
‘C was developed in 1972 by Dennis Richie while working at Bell Labs. C is
Very commonly used to program operating systems such as UNIX, Windows,
And Macintosh OS etc. It is also very useful for compiler writing.
C++ was an extension to C using OOP (Object Oriented Programming)
Concept, while maintaining the speed of C. C++ is most often used in
Simulations, such as games. It is the language of choice in today’s Computer
It was the first visual development tool from Microsoft, and it was designed to
Compete with C, C++, Pascal and any other well-known programming
Languages when it came out, Visual Basic wasn’t very successful. It wasn’t
Until Microsoft released VB 2.0 in 1993 that people really started to discover
The power of the language, and when Microsoft released VB 3.0 it had become the fastest growing programming language in the market. By now, Visual
Basic has earned itself the status of a professional programming language.
VB is most often used today to create quick and simple interfaces to other
Microsoft products such as Excel and Access without needing a lot of code.
Though it is possible to create full applications with it.
Sun Micro systems began developing a language with the primarily purpose to
Control microprocessors used in consumer items such as cable receivers.
VCR’s, toasters, and also for personal data assistants (PDA). Java offers
Powerful capabilities of network programming, Internet applications and GUI
(Graphical User Interface).
Introduction to Language Translators
Language translators are the programs that translate a high or level
Language program into machine code.
Program written in any language is first •analyzed by a special piece of
Software. This piece of software is designed by the language designer. The software
Checks the program for errors, optimizes the code and generates machine language for
That program. All the software available for this purpose can bc categorized into three
An assembler is a program that translates an assembly language program into
Compiler is a program that translates a source program (written in some
High-level programming language) into machine language (or machine code). A
Compiler first reads the whole program before executing it.
An interpreter on the other hand, looks at each line of the program, decides
What that line means, checks it for possible errors and then executes that line. If one
Of the lines is executed repeatedly, it must be scanned and analyzed each time, greatly
Slowing down the solution of the problem at hand.