Introduction
Computers are not living things that
can communicate at freewill to users, therefore in order to tell a computer
what to do and make it understand and do as such; you will need to create a
system that allows the computer to understand a task in its own terms. This can
be achieved through programming and this forms the basis of program development
and language.
Programming Language and Development
Obtaining information from a computer
requires the use of a set of instructions that orders the computer system to
produce the needed information. Basically a program is the set of instructions
or tasks that allows users to receive the needed information from a computer.
Programs are created or modified by Programmers or Developers. They use words,
symbols and abbreviations called programming languages to communicate
instructions to computer for execution. Various programming language exist with
distinct rules for writing instructions. Each of these languages is mostly
designed for specific purposes. There are two types of programming languages;
lower level and higher level languages. The major difference between the two
languages is that the former is machine dependent thus runs on a single type of
computer while the latter runs on multiple machine instructions.
The lower level language entails
machine language and assembly language which are the first and second
generation of programming languages respectively. Machine language is the only
language the computer directly understands. It uses binary digits or binary
representations. With assembly languages meaningful abbreviation known as
symbolic abbreviation codes and symbolic addresses are used.
The third generation language known
as procedural language uses instructions that tell the computer what to do and
how to do it. Arithmetic operations and English words are used to write
instructions. It uses a compiler which is a separate program to convert the
entire program to machine language before execution. Another translating
program is the interpreter which translates one line of source program at a
time. Examples of procedural languages are the C and COBOL.
A fourth generation language is a
nonprocedural language that allows users and programmers to access data in a
database. Here English-like words are used and it easier to use than the
procedural languages. An example is SQL.
Web developers use various techniques
to create a web page, in order to format documents for display on the web
developers use HTML (hypertext markup language) for browsers and
XHTML(extensible HTML) for micro browsers that is the smart phones and devices.
HTML and XHTML are not programming languages but are used to format the
contents on a web page. XML separates the Web page content from its format,
allowing the Web browser to display the contents of a Web page in a form
appropriate for the display device. WML (wireless markup language) is a subset
of XML that wireless devices use. Small programs like script, applet, servlet
etc. are developed to add dynamic contents and interactions to web pages. CGI
scripts enhance communication between the computer and the web browser. Scripts
can be written using some programming languages but some developers use
scripting languages which is an interpreted language that is easy to learn and
use. For example, Java Script, Perl etc.
Another form of HTML that allows
developers to include more graphics and interactivity without webpage accessing
the web server is the Dynamic HTML (DHTML). It allows for automatic update and
displays relatively faster.
When developing programs, developers
go through a series of activities known as the program development life cycle.
The steps are:
1. Analyze Requirements
2. Designing Solution
3. Validate Design
4. Implement Design
5. Test Solution
6. Document Solution
In designing solution developers
make sure that they will meet user requirements. A graphical or written
description of the procedures to solve the problems known as solution algorithm
or program logic is used. In structured design, the programmer typically
begins with a general design and moves toward a more detailed design.
Here, hierarchy charts are used to show program models graphically. It is
simple, reliable, readable, reasonable and easy to maintain.
Sometimes
programmers package the data and procedure into a single unit, this structure
is known as the Object-Oriented Design. Control structures are used to describe
the task a program is to perform. The basic control structures are sequence,
selection and repetition.
In
a sequence control structure, one or more actions are shown in an orderly
manner. No action can be avoided or skipped.
In
selection control structure, the program takes actions based on certain
conditions. Under this structure, if-then-else and case structure is mostly
deployed.
Repetition
controls structure enables the performance one or more actions repeatedly as
long as predefined conditions are satisfied
The
flowcharts and pseudo codes are two main design tools used in programming.
Flowcharts graphically shows the logic in a solution algorithm whiles
psuedocode uses English to convey program logic
Conclusion
In
a nut shell, programming language helps developers to create programs based on
user specification and allows user to receive the right or desired feedback
anytime they ask their computers to perform a task.
