UOG Lahore Campus: Computer Programming

Computer programming is the act of writing computer programs, which are a sequence of instructions written using a Computer Programming Language to perform a specified task by the computer.

Computer Programming is fun and easy to learn provided you adopt a proper approach. This tutorial attempts to cover the basics of computer programming using a simple and practical approach for the benefit of novice learners.

Audience

This tutorial has been prepared for the beginners who are willing to learn computer programming but they are unable to learn it due to lack of proper guidance. We are confident that after completing this tutorial, you will be at a level where you can code in C Programming language and will have a basic understanding of Java and Python programming languages as well from where you can continue further.

If you are completely new to Computer Programming, then we recommend you to read this tutorial twice or even thrice. First reading will not give you much idea, but during your second reading, you will start grasping most of the concepts and you will enjoy writing computer programs.

Prerequisites

We do not expect much from you as prerequisites, however, we assume that you have some amount of exposure to computers and its peripherals like keyboard, mouse, screen, printer, etc.

Introduction to Computer Program

Before getting into computer programming, let us first understand computer programs and what they do.

A computer program is a sequence of instructions written using a Computer Programming Language to perform a specified task by the computer.

The two important terms that we have used in the above definition are −

Sequence of instructions
Computer Programming Language

To understand these terms, consider a situation when someone asks you about how to go to a nearby KFC. What exactly do you do to tell him the way to go to KFC?

You will use Human Language to tell the way to go to KFC, something as follows −

First go straight, after half kilometer, take left from the red light and then drive around one kilometer and you will find KFC at the right.

Here, you have used English Language to give several steps to be taken to reach KFC. If they are followed in the following sequence, then you will reach KFC −

1. Go straight
2. Drive half kilometer
3. Take left
4. Drive around one kilometer
5. Search for KFC at your right side

Now, try to map the situation with a computer program. The above sequence of instructions is actually a Human Program written in English Language, which instructs on how to reach KFC from a given starting point. This same sequence could have been given in Spanish, Hindi, Arabic, or any other human language, provided the person seeking direction knows any of these languages.

Now, let's go back and try to understand a computer program, which is a sequence of instructions written in a Computer Language to perform a specified task by the computer. Following is a simple program written in Python programming Language −

print "Hello, World!"

The above computer program instructs the computer to print "Hello, World!" on the computer screen.

A computer program is also called a computer software, which can range from two lines to millions of lines of instructions.
Computer program instructions are also called program source code and computer programming is also called program coding.
A computer without a computer program is just a dump box; it is programs that make computers active.

As we have developed so many languages to communicate among ourselves, computer scientists have developed several computer-programming languages to provide instructions to the computer (i.e., to write computer programs). We will see several computer programming languages in the subsequent chapters.

Introduction to Computer Programming

If you understood what a computer program is, then we will say: the act of writing computer programs is called computer programming.

As we mentioned earlier, there are hundreds of programming languages, which can be used to write computer programs and following are a few of them −

Java
C
C++
Python
PHP
Perl
Ruby

Uses of Computer Programs

Today computer programs are being used in almost every field, household, agriculture, medical, entertainment, defense, communication, etc. Listed below are a few applications of computer programs −

MS Word, MS Excel, Adobe Photoshop, Internet Explorer, Chrome, etc., are examples of computer programs.
Computer programs are being used to develop graphics and special effects in movie making.
Computer programs are being used to perform Ultrasounds, X-Rays, and other medical examinations.
Computer programs are being used in our mobile phones for SMS, Chat, and voice communication.