Computer
Languages – Computer Awareness Notes
Introduction:
A language is the main
medium of communicating between the Computer systems and the most common are
the programming languages. Computer language or programming
language is a code used by computer programmers to communicate with a computer.
Computer language
establishes a flow of communication between software programs. The language
enables a computer user to dictate what commands the computer must perform to
process data. There are basically two types of computer languages:
1) Low Level Language
2) High Level Language
1. Low Level
Language:
Low level languages are
computer instructions or machine code very easily understandable by a computing
machine. It is mainly designed to operate and handle all the hardware and
instructions set architecture of a Computer. The main function of the Low level
language is to operate, manage and manipulate the hardware and system
components.
Machine
Language is
one of the low-level programming languages which is the first generation
language developed for communicating with a Computer. It is written in machine
code which represents 0 and 1 binary digits inside the Computer string which
makes it easy to understand and perform the operations.
Advantages
1. It makes fast and efficient use of
the computer
2. It requires no translator to
translate the code i.e. directly understood by the computer.
Disadvantages
1. All operation codes have to be
remembered
2. All memory addresses have to be
remembered
3. It is hard to amend or find errors in
a program written in the machine language
4. These languages are machine dependent
i.e. a particular machine language can be used on only one type of computer.
Assembly
Language is
the second generation programming language that has almost similar structure
and set of commands as Machine language. Instead of using numbers like in
Machine languages here we use words or names in English forms and also symbols.
For example microprocessor instruction codes. An assembly language is the most
basic programming language available for any processor. With assembly language,
a programmer works only with operations that are implemented directly on the
physical CPU.
Advantages
1. It is easier to understand and use as
compared to machine language
2. It is easy to locate and correct
errors
3. It is modified easily
Disadvantages
1. Like machine language it is also
machine dependent
2. Since it is machine dependent, there
programmer should have the knowledge of he hardware also.
2. High Level
Language:
High-level computer
languages use formats that are similar to English. The purpose of developing
high-level languages was to enable people to write programs easily, in their
own native language environment (English).
High-level languages are
basically symbolic languages that use English words and/or mathematical symbols
rather than mnemonic codes. Each instruction in the high-level language is
translated into many machine language instructions that the computer can
understand.
- Problem-Oriented
Language: These are languages used for handling specialized types of data
processing problems where programmer only specifies the input/output
requirements and other relative information of the problem, that are to be
solved. The programmer does not have to specify the procedure to be
followed in solving that particular problem.
- Procedural
Language: These are general purpose languages that are designed to express the
logic of a data processing problem.
- Non-procedural
Language: Computer Programming Languages that allow users and professional
programmers to specify the results they want without specifying how to
solve the problem.
Many languages have been
developed for achieving different variety of tasks, some are fairly specialized
others are quite general purpose. These are categorized according to their use
as:
1. Algebraic Formula-Type
Processing: These
languages are oriented towards the computational procedures for solving
mathematical and statistical problems. Examples are
1. BASIC (Basic All Purpose Symbolic
Instruction Code)
2. FORTRAN (Formula Translation).
3. PL/1 (Programming Language, Version
1).
4. ALGOL (Algorithmic Language).
5. APL (A Programming Language).
2. Business Data
Processing: These languages emphasize their
capabilities for maintaining data processing procedures and files handling
problems. Examples are:
1. COBOL (Common Business Oriented
Language)
2. RPG (Report Program Generator).
3. String and List
Processing: These are used for string
manipulation including search for patterns, inserting and deleting characters.
Examples are: LISP (List Processing).
4. Object-Oriented
Programming Language: In OOP, the computer program is divided into objects. Examples are:
- C++
- Java
5. Multipurpose Language: A
general purpose language used for algebraic procedures, data and string
processing. Examples are:
1. Pascal (after the name of Blaise
Pascal).
2. PL/1 (Programming Language, version
1).
3. C language.
6. Simulation: These
may be written in algebraic or multipurpose languages. Examples are:
1. SPSS (Statistical Package System Simulator).
2. GPSS (General Purpose System
Simulator).
7. Visual Programming
Language
These programming
languages are designed for building Windows-based applications.Examples are:
- Visual Basic
- Visual Java
- Visual C
Advantages: Following are the advantages of a
high level language:
1. User-friendly (people based)
2. Similar to English with vocabulary of
words awl symbols therefore it is easier to learn.
3. They require less time to write
4. They are easier to maintain
5. Problem oriented' rather than
'machine' based
6. Shorter than their low-level
equivalents. One statement translates into many machine code instructions.
7. Program written in a high-level
equivalent can he translated into many machine language and therefore can run
on every computer for which there exists an appropriate translator.
8. It is independent of the machine on
which it used i.e. programs developed in high level language can be run on any
computer.
Disadvantages: There are certain disadvantages also Inspite these
disadvantages high-level languages have proved their worth. The advantages
out-weigh the disadvantages by far, for most applications. These are:
1. A high-level language has to be
translated into the -machine language by a translator and thus a price in
computer time is paid.
2. The object code generated by a
translator might be inefficient compared to an equivalent assembly language
program
Compiler & Interpreter
These are the programs
that execute instructions written in a high-level language. There are two ways
to run programs written in a high-level language. The most common is to compile
the program; the other method is to pass the program through an interpreter.
a. Compiler
A compiler is a special
program that processes statements written in a particular programming language
called as source code and converts them into machine language or “machine code”
that a computer’s processor uses.
Compiler translates high
level language programs directly into machine language program. This process is
called compilation.
b. Interpreter
An interpreter translates
high-level instructions into an intermediate form, which it then executes.
Compiled programs generally run faster than interpreted programs. The advantage
of an interpreter, however, is that it does not need to go through the
compilation stage during which machine instructions are generated. This process
can be time-consuming if the program is long.
Smart Review Points (Exam Point of view)
- The first computer language for
electronic devices was short code.
- The first of the major languages
appeared in the form of FORTRAN.
- FORTRAN stands for Formula
Translation system.
- FORTRAN language was designed at IBM,
for scientific computing.
- The language used for programs
that benchmark and ranks the world's fastest super computers is FORTRAN.
- The name COBOL stands for "COMMON
BUSINESS ORIENTED LANGUAGE".
- The language which was referred
as "the mother of the COBOL language" was FLOW - MATIC language.
- LISP stands for LIST
PROCESSING language.
- LISP language was designed for Artificial
Intelligence research.
- The first language to have
format grammar was ALGOL.
- ALGOL mean ALGORITHMIC
Language.
- ALGOL is a high level language
designed specially for programmingScientific Computations.
- Pascal language was named in
honor of Blaise Pascal.
- Pascal language was developed by Niklans
Wirth.
- A small and efficient language
intended to encourage good programming practices is Pascal.
- A general purpose programming
language which was developed by Dennis Ritchie was 'C' language.
- C++ language was known as Object
Oriented Programming or OOP.
- C++ is most after used in
simulations, such as games.
- C++ is sometimes called a hybrid
language.
- One of the preferred programming
languages to develop professional applications is C++.
- Java is a programming language
developed by James Gosling.
- Java language was developed to
facilitate communication with the interactive T.V.
- Visual Basic (VB) was derived
from BASIC.
- BASIC is a very limited scope language
and was designed for non - computer science people.
- The heart of VB is the form or
blank window on which some components are drag and drop. Those items are
known as Widgets.
- Perl has often been described as the 'Duct
tape of the Internet'.
- Perl was developed by Larry
Wall in 1987.
- PERL stands for Practical
Extraction and Reporting Language.
- BASIC means Beginner's All
purpose symbolic instruction code.
- Ada is a structured, statically
typed, wide spectrum, object oriented high level computer programming
language.
- Ada is an international standard.
- CORAL stands for Computer On -
line Real - time Applications Language.
- Coral 66 is a general purpose
programming language based onALGOL 60.
- Coral is specifically intended
for real time and embeddedapplications.
- PHP is a general purpose server side
Scripting language Originally designed for Web development to produce
dynamic Web pages.
- PHP originally stood for Personal
Home Page.
- At present, PHP is said to stand
for Hypertext Pre - Processor.
- HTML stands for Hyper Text
Markup Language.
- HTML is for displaying web pages
and other information that can be displayed in a web browser.
- CSS stands for Cascading Style
Sheets.
