COMPUTER SCIENCE FOR ROOKIES

By Angel Bahabwa

Computer science for rookies is a book that will explain the basic concepts of computer science. It is organised in question and answer form with well and briefly explained concepts to enable the rookie star understand the major concepts of computer science. 

All the basic concepts of computer science are covered in this book. It is simplified enough to enable a person who has never heard any concept of computer science can read and understand.

It is supplied with enough examples for worked out programs. In short, it is a book you can read at last moment and excel in computer science.  

• Language: English
• Publisher: Angel Bahabwa
• Release date: Jun 16, 2019
• ISBN: 9781393464679

Angel Bahabwa

Angel Bahabwa is a motivational speaker, entrepreneur, education activist and social analyst. He loves reading and sharing knowledge with people. He has worked with various organizations in East Africa fronting the need for specialized education and has hosted several radio programs on social economic development.

Book preview

Introduction

After I finished writing my book " GET TO THE TOP (THE ART OF EXCELLING IN YOUR ACADEMICS)" I was challenged to get back to school to prove that the ideas I had written were truly working. I reluctantly admitted to try and prove that the principles I was fronting were truly working and at the end, I proved it right. This book is research notes that I made to enable me succeed at proving that the principles portrayed in the book " GET TO THE TOP "

It is hard to think that a person can study computer science in just three months and perform well in the national examination beating those who had studied it for three years. Well I did it and I got a straight C. It was unbelievable to me but inside me I had a strong belief that I was going to make it when every person was discouraging me.

At the beginning I realized that if I was going to make it, I had to get the best notes and I should be close to the teacher to explain to me all the many things I had to know. The science subject that needed to be studied for three years, I had to study it in three months and study other subjects like math! This was the most complicated task I had chosen to get involved in. It was indeed stretching my abilities. I knew that with the help of the teacher I would still make it and I set out to always hunt him but later I confronted the hard truth.

The hard truth was that the books to read were many and the notes present were quit complicated. The teacher was not readily available to answer the many questions I had to ask. I decided to make my own notes because the books that were present were full of verbiage that were complicated to understand. I reasoned out to make my own book that would help me understand the hard concepts. It took me a complete month to organize this small book that was covering the topics that were necessary to make me pass the subject well. I aimed at a B and I got a C.

I have faith that if a student reads this book well, he is able to understand the most important concepts in computer science and get an A in his final exams. If I managed to read it for two months and get a C, what about a student who could give it enough time.

My intention of writing this book is to help students understand the major concepts in computer science within a short time to enable them succeed in their national exams. It contains simplified answers for any student to understand and it is organized in a question and answer format. All answers in this book were worked out and proven to be right. Take time and study and the results will please you.

Remember these notes cover the most complicated parts of computer science and are simplified in a way that a student who always performs below average can read and understand it. Make it your hand book. Whenever you get spare time, pull it out and read through. If you are going to perform better than I did, you have got to do more than I did. In the course of two months, I was able to read this book and complete it and it enabled me pass the subject well. A student who requested a copy of this book and made the best of it, got a straight A. It is your turn now to excel in computer science.

Don’t rush to complete the book. Read every concept with an aim of understanding it. Just don’t panic. Take time and read every question reflecting on each and every answer. With faith and hard work plus some luck, everything is possible.

Dedication

To all students who try to find ways to excel at subjects they set to study.

Computer Programming

Qn. What is computer program?

Computer program: Is a sequence of instructions written to perform a specific task on a computer.

Qn. what is computer programming?

It is a process that leads from an original formulation of a computing problem to executable computer programs.

A computer programming: is a process of a given instruction to a computer in order to solve and execute derived task.

Qn. Give the difference between source code and object code.

1)  Source code: is the fundamental component of a computer program that is created by a programmer.

2)  Object code: is a set of instruction codes that can be understood by a computer.

Qn. Explain the stages in program development.

1)  Define or understand the problem: first of all, you must understand the problem, if you don’t know the problem, you can’t find the solution.

2)  Analyze the problem: once you know what the problem is, you can analyze it and make a plan to resolve it.

3)  Develop an algorithm and flowchart:  this is a process whereby a set of instructions are used to produce a solution to a given problem.

4)  Writing the computer’s code:  following the algorithm and flowchart. This is the next step where you write the codes for the program to make it work.

5)  Compiling and debugging the program: once the program coding is completed, you compile your program means you translate the source code to object code and if there are errors, you debug them.

6)  Running the program: to run an application means to execute it and check, if using some data, it is working with the correctness of the program.

7)  Implementation and documentation: when those steps are achieved, you could implement your application. You may add the explanation on how program works and how to use it.

Qn. Explain the term stored procedure

Stored procedure: is a group of sql statements compiled into a single execution plan (or are set of structured query language statements that perform particular task).

Qn. Briefly, explain the advantages of using stored procedures.

1)  Helps to build powerful database applications.

2)  Provide better performance.

3)  Higher productivity.

4)  Ease of use.

Qn. State the difference between logical error and run time error.

a)  Logical error: is a type of programming error that happens when application runs but produces incorrect result. Example the output of additional instead of subtraction.

b)  Run time error: is a type of programming error that caused by attempting to do impossible arithmetic operations; such calculating non-numeric data, dividing a number by zero, or find the square root of a negative number.

Qn. Give the difference between local variables and global variables.

1)  Local variables: are variables that are declared inside the function.

2)  Global variables: are variables that are declared outside the function.

Qn. What is the meaning of debugging in programming language?

Debugging means to correct or remove errors if there are in the program

Qn. Define Identifiers and state the rules of valid identifiers

Identifiers: are names given to variables which distinguish them from all other variables.

Rules for valid identifiers

1)  Start with a letter.

2)  Consist only of letters, the digits 0-9, or the underscore symbol (-).

3)  Not be a reserved word.

Qn. What are the two types of functions?

1)  Library functions

2)  User defined functions

Qn. Array can be categorized into two part show them?

1)  Single dimensional array.

2)  Multi-dimensional array.

Qn. What is a pure virtual member function?

A pure virtual member function: is the abstract class whose pure virtual method has to be implemented by all the classes which derive on these.

OPERATING SYSTEM

Qn. What is an operating system?

An operating system is a program that acts as an intermediary between the user and the computer hardware. The purpose of an OS is to provide a convenient environment in which user can execute programs in a convenient and efficient manner.

Qn.2. What are the different operating systems?

•  Batched operating systems

•  Multi-programmed operating systems

•  Timesharing operating systems

•  Distributed operating systems

•  Real-time operating systems

Qn.3. What are the basic functions of an operating system?

Operating system controls and coordinates the use of the hardware among the various applications programs for various uses.

Operating system acts