INTRODUCTION TO COMPUTER PROGAMMING IN QBASIC LANGUAGE

INTRODUCTION TO

COMPUTER PROGAMMING IN QBASIC LANGUAGE

OVERVIEW:

There are two facts that dive human reasoning and thoughts. Basically, human beings cannot speak or write in computer language and computers cannot speak or write in human language, therefore an “Intermediate” language had to be developed to allow people to communicate with the computers. These intermediate languages are known as programming language which allows computer programmers (Users) to direct the activities of the computer. Thus, programming languages are structured around unique set of rules that direct the computer to perform a specific task. A typical instruction in a programming language consists of two parts:-

1. An operation code

2. Some operands

The operation code tells the computer what to do such as add, subtract, multiply and divide. The operands tells the computer the data items involved in the operations. E.g. considering the instruction a = b + 5, the ‘=’ and ‘+’ are operation codes while ‘a’, ‘b’ and ‘5’ are operands. Some computer uses many types of operation codes in their instruction format and may provides several methods for doing the same thing.

Nevertheless, there are four basic types of instruction namely:

1. Input – output instructions

2. Arithmetic instructions

3. Branching instructions

4. Logic instructions

Summary:-

An input instruction directs the computer t accept data from a specific input device and store it in a specific location. An output instruction tells the computer to move a piece of data from a computer storage location and record it on the output screen. All of the basic arithmetic operations can be operated by the computer. Branch instruction causes the computer to alter the sequence of execution of instruction within the programme. Logic instructions allow the computer to change the sequence of execution of instruction, depending on conditions built into the programme by the programmer.

TYPES OF PROGRAMMING LANGUAGE

The effective utilization and control of a computer system is primarily through the software of the system. Just as system software directs the internal operations of the computer while applications software allows the programmer to use the computer to solve user made problems.

Programming languages which means the primarily means of human vs computer communication which have evolved the early stage programmers enter instruction into the computer in a language similar to that used in the application software. Computer programming language can be classified into the following categories:

i) Machine Language

ii) Assembly Language

iii) High level symbolic Language

iv) Very high level symbolic Language

Summary:-

Machine language programmes allows the programmer to take advantage of all the features and capabilities of the computer system for which it was designed. A machine language is computer dependent. Thus, it is the first generation computers language.

Assembly language is as well known as the low level programming language. This allows the programmer to remember the operations codes easily than when expressed strictly as binary numbers. It must be translated into a machine language using a system software programme called an assembler. They are the second generation computers languages.

High level language are machine independent, i.e. it can run on a variety of computers. Its instructions do resemble English language statements and the mathematical symbols are the symbols used in ordinary mathematics. Examples are fortran, basic, cobol, pascal, algol, ada and pi/i. They are the third generation computers language. Very high level language are the fourth generation computers language that allow the user to specify what they require, rather, than describing the procedures by which requirements are met. It also offers the user an English-like set of commands and simple control structures in which to specify general data processing or numerical operations.

PROGRAMMING MICROCOMPUTERS IN BASIC LANGUAGE

There are some computer languages which are capable of supporting both scientific and business data processing efficiently and effectively. An example of such computer language is basic.

Basic programming language is an easy- to-go use “friendly” language whose instructions resembled elementary algebraic formular augmented by certain English Language keywords such as input, read, print, Goto, if, then and so on.

WHAT DOES QBASIC STANDS FOR?

It is an acronyms for:

Q - Quick

B - Beginner’s

A - All-purpose

S - Symbolic

I - Instruction

C - Code

DEFINITION:

QBASIC is one of the many versions or dialects of the basic language which retains the user friendly environment characterizes by the implementation of basic language. This means that QBASIC runs on the windows to facilitate the storing of coded programmes in the secondary memory for retrieval with the ability to support real integer and string data typed. It also contains necessary tools that are required for the manipulation of matrices, graphs and images.

A BRIEF HISTORY OF QBASIC

QBASIC came into existence in the year 1960’s. It was developed by two mathematical professors and technicians named Prof. John Kemeny and Prof. Thomas Kurtz, at Dartmouth College, Hanover, NH 03755 USA (603) 646-1110 (E-mail): contact@dartmouth.edu

The story goes that the students were having difficulty learning FORTRAN so the professors decided that creating a language from scratch would be an excellent teaching tool for the students. The result was BASIC, which was eventually placed in the public domain.

On the contrary, QBASIC is a programming language invented and modified by Bill Gates and Hitler designed to make a program that would launch missiles from outer space in hopes of destroying the cancer that is killing /b/. Unfortunately, since the earliest versions of QBASIC could only display text, they had to settle for a word processing program that could WRITE SHIT ON YOUR SCREEN instead.

Bill Gates and Paul Allen had something different in mind. In the 1970's when M.I.T.S.'s Altair personal computer was being conceived Allen convinced Gates to help him develop a Basic Language for it. When M.I.T.S. answered with interest, The future of BASIC and the PC began. Gates was attending Harvard at the time and Allen was a Honeywell employee. Allen and Gates licensed their BASIC to M.I.T.S. for the Altair. This version took a total of 4K memory including the code and data used for a source code. Gates and Allen then ported Basic to other various platforms and moved back to their hometown of Seattle where they had attended grade school together. It was at this time that the Microsoft Corporation began it's reign in the PC world.

WHAT IS QBASIC PROGRAMME ALL ABOUT (AIMS / FOCUS OF QBASIC)

1. It is a friendly people – orientated easy to learn programme and fun to use.

2. It is operated in an ‘English-like’ commands

3. It is very powerful and popular- high level programming language.

4. It runs on all microcomputers.

5. It provides enough steps for coding a sample progrommes.

6. It solves practical mathematical equations applicable to scientist mathematics.

7. It allow the user to write and play around QBASIC

8. Its operations share similar ideas on how to operates other basic programmes such as visual basic, c plus, java, etc.

MORE ADVANCED ADVANTAGES OF PROGRAMMING LANGUAGE

1. It is friendly, that is, it is people-orientated. It is easy to learn and fun to use. Any well – organized person can learn to programme in BASIC.

2. It is very flexible, allowing the programmer to develop new programmes and to alter existing programme with relatively little effort.

3. It is well suited for use in an interactive environment. This includes dedicated microcomputer applications as well as large computer time sharing applications.

4. It is universally available, on both large and small computers. It has become the standard programming language for most microcomputer applications.

5. The commonly used features of BASIC are relatively standard, though there are some differences between one versions of Basic to another.

LOADING QBASIC

Loading QBASIC is very easy depending on your computer. It is commonly found in all computers except vista. But one can purchase it from CD ROM and install it.

Method: 1

Loading through Ms. DOS

· Click ‘start’ button

· Click ‘run’

· Type ‘cmd’ and select Ok

· Type ‘cd\’ and press enter

· Type ‘qbasic’ and press enter key ones

Note:

If Ms. DOS display ‘invalid command’, it means QBASIC is not installed on your computer. But if QBASIC screen pop-up appear, two choices will be shown.

Alternatively:

Method: 2

Loading through “Windows Desktop”

· Double – click on “QBASIC” or “SHORTCUTS TO QBASIC

· Double click QBASIC and choose to run if available

QBASIC SCREEN IDENTITY:

If you press the <Enter> key, you will be taken to the QBASIC HELP menu where you find information that concerns QBASIC operations/statements. While pressing the “Esc” key, the pop-up box will disappear and QBASIC opens up blue painted environment.

In addition, one will find the menus of QBASIC display after the title bar.

QBASIC MENU

Diagram:

Below the menu is the blue painted area called the process. QBASIC process is the desktop where the user operates the demand and coded programmes but the user will not see the outcome / result displayed. It is expected that the user sees the outcome of his coded programme on the “Black & White” screen called the output.

Down below the process screen (blue painted) space is the line of “Immediate”

IMMEDIATE LANE:

Diagram:

The immediate line cannot process any data, therefore it is “no go area”. Nothing works there. It is useless going there to type or code your program.

OUTPUT SCREEN

Diagram:

At the output screen the user is prompt to press any key to return back to the process when the user have finished viewing the outcome of his/her programme via the message “Press any key to continue”

TERMINOLOGIES OPERATED ON QBASIC PROGRAMME

1. PROGRAMMING A COMPUTER IN QBASIC

Programming a computer in QBASIC means that you tell the computer what you want it to do. In other to tell the computer what to do in QBASIC, you need those special words called commands. When you put all the needed/demand special words in typing together in other to execute something, then it can be regarded as coding. Therefore when the user writes or code a programme on QBASIC is known as programming.

2. BASIC RESERVED WORDS

These are commands or keywords that acts in the capacity of commands and execution, when typed. QBASIC uses it to execute your written programmes. For instance, some acts in the capacity to calculates, to show final results, to correct errors, to allow writing of numbers or words to be a heading, etc.

On the contrary, these reserved words only acts as commands and execution but in terms of typing your programmes, do not use those reserved words, because if typed it will cause your programmes written on the process (blue painted space) to malfunction.

3. Key Basic Statement

Key basic statement are commands or keywords required to type as you code/write your programmes on the blue painted space which will later turn into CAPITAL letters meant for execution of calculation, as well as running the written/coded programmes.

In addition, each of the basic statement you type must be on a line and each line must be assign, a number known as LINE number. These line numbers gives an order of sequence how QBASIC should execute her programme. Usually a positive multiples numbers from 0, - infinity are expected to used. This can be optional to the user.

EXAMPLES OF KEY BASIC STATEMENTS OPERATED IN QBASIC CODED PROGRAMMES

1. Rem Statement:

Rem is a special keyword known as remark. Sometimes when a programmer write long programme, he or she will like to leave notes inside their programme so that they can remember why they did certain things. So to leave a note that explains certain things, use remark. QBASIC knows that when it sees ‘Rem’ it does not have to do what you wrote after it on that line.

2. Cls Statement:

Cls means clear screen. If you run a programme from QBASIC, everything that was on the screen before you started QBASIC will show (i.e. written on the screen), that is why we need the keyword cls.

3. List Statement:

List statement is used to examine the programme and correct errors before it is executed. This is because QBASIC displays and execute programmes line-by-line according to the numbers used.

4. Print Statement:

Print is one of the most useful and powerful commands in QBASIC that causes the information typed between the double quote (“ “) to be sent to the screen or visual display unit end result where the users sees or runs the programme to get the final results.

In addition, when Print is typed on the line number without double quote (i.e. line number bearing print), QBASIC will provide one empty space between such line and the next line at the output.

5. Input Statement:

This statement allows information to be typed using the keyboard of the computer in generating the needed data before the final answer will appear at the output. The computer executes this input statement by using a representative question mark ( ? ) waiting for the data (i.e. figures) at the output screen to be typed in.

6. Read Data Statement:

This statement allows information be followed by the word “read” while the figures will be typed/supply at the same line typing of “Data”, before the final answer be displayed on the V.D.U. Screen.

7. Let Statement:

This statement will cause the arithmetic expression on the right hand side typed before an equal sign ( = ) be stored as the result (answer that belongs to) the variable at the left of the equality sign.

8. End Statement:

This statement stops the execution of the programme. That is to say, end statement tells the computer that the written/coded programme done on QBASIC blue painted space (process) has come to an end.

9. Dim Statement:

Dim means dimension. It is the statement used to reserved different locations of stored values when many locations are involved in a programme by using just one variable.

10. Colour Statement:

Colour is a statement used to change the colour appearance of the words on the screen when you run the coded programme. This allows for fun, making sure you add colour when the need arises.

Nevertheless, the colour list table is as follows:-

To paint	Number to used	To paint	Number to used
Black Blue Green Cyan Red Magenta Brown White	0 1 2 3 4 5 6 7	Grey Light blue Light green Light cyan Light red Light magenta Yellow Bright white	8 9 10 11 12 13 14 15

11. Making Sound in QBASIC

Sound is an easy statement used to produce sound when you run your programme. To use the keyword sound, you must type (enter) two (2) numbers. The first number is the frequency of the sound in high or low capacity (kw) which ranges from very low frequent (37kw) to (32767kw) very high frequency. The second number is how long the sound should last.

12. Drawing Pictures/Objects or Shapes with QBASIC with:

i) The Screen Statement:

Before you even start drawing object, shapes or pictures, you have to tell QBASIC that you want to draw pictures. To do this, you need to used screen statement by assigning number to it. Number 12 (mode 12) is one of the screen numbers that is used to draw pictures.

ii) To Draw Line(s):-

Line Statement is used to draw lines but you must specify by typing where the line will starts and ends.

iii) Drawing a rectangular box in conjunction with line statement:

The line statement can also be used to draw other shapes for instance it can be used to draw boxes filled with colours or empty.

iv) Drawing a Circle:

Another very important shape is circle. The keyword Circle can be used to draw a circular shape but you also need to specify where the centre of the circle should be and how far from the centre it will be drawn and to the edges it will covers.

Watch all these statements when you start the practical.

ELEMENTS OF QBASIC

Every programming language consists of some important elements which are required to make a programme be executed. Therefore elements are those typing that are required to make a coded programme function properly, before running it to see your answers. These elements can involves character sets, keywords, constants, variables, operators and expressions.

CHARACTER SETS:

These are typing required when coding a programme which can be type in alphabets both in smaller and capital letters, numbers that ranges 0 to 9, and infinity. Special symbols and signs are also part of character set in which each performs meanings and various functions and makes your program of standard.

Examples of special symbols and signs used as a character set in QBASIC is shown below:-

Signs	Signs	Signs	Signs
+ - * / \ ^	“ “ ‘ , ; : =	> < ( ) . ?	s % $ ! # Blank space

CONSTANTS

They are the data or the values stored inside variable coded on qbasic program that cannot changed during the program execution except for numbers. The data may be a letter, words, numbers, special symbols but they are stored inside a variable name which QBASIC will not changed the way you type it, except it is numbers. Why? Because numbers when stored as constants, QBASIC can perform mathematical calculation on it.

In QBASIC coding of programme, constants are grouped into two broad headings:

a) String Constant

b) Numeric Constant

String Constants:

It is a letter, words, numbers, combination of letters with numbers or special symbols enclosed in double quotes (“ “) stored inside a variable name in which mathematical operations cannot be done on it. It can also be used to express statement on a program typed to QBASIC. For instance, “B”, “Apple”, “Symbol No. 10208”, “Welcome to QBasic World!!!”, etc.

Numeric Constants:

Numeric constant refers to a number with or without decimal point, stored inside a variable name in which mathematical operations can be done on it. Numbers written in thousands to QBASIC will not consists of separator (,) which also can not be enclose in double quotes. Generally, mathematical and logical operations can be done on them e.g. 101, 105.50, 720, 45603, etc.

VARIABLE:

In QBASIC, a variable is a place on the computer memory which has a name and stores data temporarily. On the otherhand, a variable is an entity that stores data needed to be used in a program. Each program defines different number of variables. The value of a variable can be change during the execution of the program. On declaring (i.e. typing) a variable, one will need to determine the type of data which QBASIC will stored inside the variable.

There are mainly two types of variables declaration. They are:-

a) String variable

b) Numeric variable

String Variable:

String variable stores string data (i.e. quotation statements) with a string variable name declare on that same line whereby mathematical and logical operations cannot be done on it as directed by the declaration symbols of dollar sign ($).

Numeric Variable:

A numeric variable stores number data inside it variable name that mathematical and logical operations can easily be done on it as directed by its declaration symbols typed.

Example of numeric variable declaration:

It can be expressed under four headings, namely, Integer, long integer, single precision and double precision variable.

For integers, it stores short whole number with the sign of percentage (%) typed to the variable name. Long integer stores large range of whole numbers with ampersand (&) declaration, for single precision, it stores single decimal numbers with or without declaration of exclamation mark (!) and for double precision, it stores large decimal numbers declares with the use of hash sign (#)

RULES FOR TYPING A VARIABLE TO QBASIC

1. Variable names typing can have maximum of 40 characters in length typed together without space.

2. Variable names can have alphabets, numbers and alphanumeric on line numbers.

3. Variable name must begin with a letter

4. Variable names cannot begin with fn or Fn alphabets for example, fnames$, fnum, etc. It is because fn causes the to calculate frequency number of statistic data. Don’t use it as a variable name.

5. Variable names cannot be served words.

6. Variable names may be ended with type declaration characters like $, %, &, !, and #

OPERATORS

Operators are symbols that indicate the type of mathematical operations QBASIC has to perform on the data or values of the variable. In QBASIC there are four types/branches of operators used on coded program namely: Arithmetic, Relational, Logical and String operators.

Arithmetic operators:

These are all the general mathematical signs used to perform simple and practical mathematical calculations like addition, subtraction, division, multiplication, exponents, etc

Example 1:

Operation	Operators	Example	Results
Addition Subtraction Multiplication Division Integer division Exponential Modular division	+ - * / \ ^ Mod	5 + 8 8 – 6 5 * 4 8/2 9\2 4^3 7 Mod 3	13 2 20 4 4 64 1

Relational Operators:

They are operators used to perform comparison on two values of the same typed statements. E.g.

Operators	Relation	Examples
= > < >= <= <>	Equal to Greater than Less than Greater than or equal to Less than or equal to Not equal to	A = B, A$ = B$ A > B, “CAT” > “RAT” A < B, “CAT < “CAT” A >= B, X$ >= Y$ A <= B, X$ <= Y$ A$ <> B$, X <> Y

Logical Operators:

It combine two or more relational expression to evaluate a singe value as true (non zero answer) or false (zero answer). For example:

And operation:

When all the results (statements) returned are true.

Statement 1 (for P)	Statement 2 (for Q)	Results (P & Q)
F T F T	T F F T	F F F T

Or operation:

It return true if any one of the relational statements expressions return true. E.g.

Statement 1 (for A)	Statement 2 (for B)	Results (A & B)
F T T F	T F T F	T T T F

Not Operation:

It operates on one statement operand and returns true if the logical statement returns false. E.g.

Statement 1 (for A)	Result (for Not A)
F T	T F

STRING OPERATOR

String joins two or more than two string data (sentences) together to form a simple or compound sentences.

E.g.

String data (for A$)	String data (for B$)	Results (A$ + B$)
“Wel” “50”	“come” “45”	Welcome 5045

The plus sign (+) is used as the string operator as the act of combining two strings together which can also be known as as concatenation.

EXPRESSION

It is the combination of operators, constants and variables that is evaluated to get a result. The result is string data, numeric data or logical value and can be stored in a variable. E.g.

(A + B) > C

A >= B + C

u = t + ½ etc

Note, expression can come from any side of the mathematics, some from linear simultaneous equation, algebra, statistics, trigonometry, etc.

Example of algebra expression:

It must be converted into QBASIC expression and interpretation before the result is shown at the output.

A = L X B A = L * B

P = 2(L+B) P = 2 * (L + B)

I = (P X T X R)

100 I = (P * T * R)/100

V = 4 pi r³

3 V = 4/3 * (PI * R ^ 3)

V = pr²h V = PI X r ^ 2 * h

ORDER OF OPERATION

The order of operations is the order (due process) in which all algebraic expression should be simplified.

For instance on QBASIC:

Parenthesis

Exponents (and Roots)

Multiplication and Division

Addition and Subtraction

[PEMDAS]

Alternatively:

Brackets

Exponentiation

Division and Multiplication

Addition and Subtraction

[BEDMAS]

Note:

Be aware that multiplication does not always come before division, and addition does not always come before subtraction. For example.

3 X 3 – 5 + 2

Your working will always starts from left to right.

You work like this. First notice that there is no parenthesis or exponents, so we move to multiplication and division. There’s only one multiplication, so we do that first and end up with 9 – 5 + 2

Now we move to addition and subtraction, so finally we do the subtraction to get 4 + 2 and finally the addition to give 6. Thus the order becomes: [PEDMSA]

Example 2: 75/5^(3-1) Using the PEDMAS

Solve for bracket (parenthesis) (3 – 1) = 2

= 75/5^2

Solve for exponentiation (5^2) = 25

=75/25

Finally, solve for division =75/25

= 3

Example 3:

In this example chose the student that solves his/her expression correct.

Student 1 student 2

3 + 4 x 2 3 + 4 x 2

= 7 x 2 = 3 + 8

= 14 = 11

Student 1 is wrong and student 2 is right in the order of operation.

LET’S PRACTICE

COMMON PRACTICAL QUESTIONS AND ANSWERS ON HOW TO CODE QBASIC PROGRAM

ALWAYS RUN YOUR PROGRAM (BY PRESSING F5 KEY) AT THE END OF YOUR CODED PROGRAM TO QBASIC BLUE PAINTED SPACE.

1. Write or code QBASIC program that demonstrates the steps or procedures involve to prepare an office tea breakfast with the results shown at the output screen.

Solution:

5 REM – Example 1

10 REM – Coding a program that illustrate

15 REM – how to prepare office tea breakfast

18 CLS

20 LET A$ = “Wash the kettle”

25 LET B$ = “Add clean water into the kettle”

30 LET C$ = “Heat the kettle for 15 minutes”

35 LET D$ = “Check if the water is boiling”

40 LET E$ = “If the water boils after 15 mnutes”

45 LET F$ = “Add coffee, sugar and milk”

47 PRINT

49 PRINT “Directives to prepare office tea”

50 PRINT “………………………………………..”

53 PRINT

55 PRINT “The first procedure is to “; A$

60 PRINT “The next procedure is to “; B$

63 PRINT “The next procedure is to “; C$

65 PRINT “The next process is to “; D$

68 PRINT “The next process is to “; E$

70 PRINT “The last procedure is to “; F$

75 END

2. Write a simple program that illustrate the below comment:

If Month = 11, 12, 1 or 2 (November, December, January, or February), then the word, “Cool Season” appear on the screen. If month = 3, 4, or 5 (March, April, or May), then the words “Hot Season” appear on the screen. If month is any number from 6 to 10 (June to October ), then the words “Wet Season” appear on the screen.

Solution:

DIM Month AS INTEGER

CLS

REM – Program to predict season

INPUT “Enter the number for season as: “, Month

SELECT CASE MONTH

CASE 11, 12, 1, 2

PRINT “Cool Season”

CASE 3 TO 5

PRINT “Hot Season”

CASE 6 TO 10

PRINT “Wet Season”

CASE ELSE

PRINT “What kind of season is demanded”

END SELECT

Alternatively:

3. Write a program that asks for a score then prints the grade assigned to the score.

Solution:

DIM Score AS INTEGER

CLS

INPUT "Enter The Test Score: ", Score

SELECT CASE Score

CASE IS >= 97

PRINT "Grade A+"

CASE 93 TO 96

PRINT "Grade A"

CASE 90 TO 92

PRINT "Grade A-"

CASE 87 TO 89

PRINT "Grade B+"

CASE 83 TO 86

PRINT "Grade B"

CASE 80 TO 82

PRINT "Grade B-"

CASE 77 TO 79

PRINT "Grade C+"

CASE 73 TO 76

PRINT "Grade C"

CASE 70 TO 72

PRINT "Grade C-"

CASE 67 TO 69

PRINT "Grade D+"

CASE 63 TO 66

PRINT "Grade D"

CASE 60 TO 62

PRINT "Grade D-"

CASE ELSE

PRINT "Fail"

END SELECT

4. Write a program with the comment: I am 11 years old, soon I will grow up and be 25.

Solution:

CLS

AGE = 11

PRINT “I am”; AGE; “years Old.”

AGE = 25

PRINT “But I will grow and soon will be “; AGE

END

5. Write a program that display today’s date in the date format of dddd/mmm/yyyy

Solution:

CLS

INPUT “Enter a year”; year

INPUT “Enter a day”; day

INPUT “Enter a month”; month

PRINT “The year is “; year

PRINT “The month is “; month

PRINT “The day is “; day

PRINT “-or-“

PRINT “The day is”; day; “/”; month; “/”; year

END

ALGEBRAIC EXPRESSION

6. How can the following formulas be converted to its QBASIC equivalent?

a) a = 3 + 3

4 + 4

E.g.

LET a = (3+3)/(4+4)

b) x = (a – b)(a – c)²

E.g.

LET x = (a – b) * (a – c) ^ 2

¹/₃

c) f = a

E.g.

Let f = a ^ ( 1 / 2 ) / b ^ ( 1 / 3 )

d) d = (8 – x²) - (4 x 2 – 1)

(x – 9) x³

E.g.

Let d = ((8 – x ^ 2) / ( x – 9) – (( 4 * 2 – 1) / (x ^ 3)

TRIGONOMETRY / CONSTRUCTION / TRIANGLE QUESTIONS.

7. Write a program that calculate the area and circumference of a circle on the following values for radius (12, 14, 15, 22 and 45 respectively).

Solution:

REM

‘ Author: Sir Isaac

‘ Class: Computer science 404

‘ Date: 07/09/2011

‘

‘ Purpose:

‘ This program will calculate the Area and circumference of a circle

‘ after receiving the value for the radius from the user.

‘

‘ (a) Start

CLS

‘ (b) Declare variable, define known values

DIM radius AS DOUBLE ‘ Radius

DIM PI AS DOUBLE ‘ Pi

DIM Circumf AS DOUBLE ‘ Circumference

DIM Area as DOUBLE’ Area

PI = 3.141593

COLOR 9

‘ (c) Get Required data from user

PRINT “This program calculates the Area and Circumference of a circle”

INPUT “What is the radius of the circle”; radius

‘ (d) Make the calculation

Circumf = 2 * PI * radius

Area = PI * radius ^ 2

‘ (e) Send the results to the screen for the user

COLOR 2

PRINT “For a circle of radius”; radius;

PRINT “and using a value for PI as”; PI

PRINT “The calculated circumference is “; Circumf

PRINT “The calculated Area is “; Area

‘

‘ (f) Stop

8. Write a program to express these equation

y = a(b – c)²

d + 2

where a = 2, b = 8, c = 4 and d = 2

Solution:

5 REM

10 CLS

15 a = 2

20 b = 8

25 c = 4

30 d = 2

35 e = a * (b – c) ^ 2

40 f = d + 2

45 y = e / f

50 PRINT “Your answer is “; y

55 END

ADVANCED FEATURES TO CODE INTERVIEW PROGRAM

9. Write a program to illustrate an interview with the user to make the right choice based on your instruction.

Solution:

10 REM – Interview program

20 CLS

30 INPUT “Please enter your first name”; N$

40 INPUT “Are you born again? Answer Y or N”; A$

50 IF A$ = “Y” THEN 70

60 IF A$ = “N” THEN 90

70 PRINT N$, “You’ve made the right choice!”

80 GOTO 100

90 PRINT N$, “You need to get born Again”

100 END

CODING LINEAR SIMULTANEOUS EQUATION ( THE ALMIGHTY FORMULA)

10. Write a program to solve the below quadratic linear equation

x = -b ± Ö b² – 4ac

Where 3x² + 8x – 16 = 0 find x.

Solution:

5 REM – Program to evaluate quadratic formula

10 CLS

20 INPUT “Enter the number of 1^st coefficient of x”; a

30 INPUT “Enter number of second coefficient of x”; b

40 INPUT “Enter number of third coefficient of x”; c

50 d = - b + SQR (b ^ 2 – ( 4 * a * c))

60 e = 2 * a

70 f = - b – SQR (b ^ 2 – (4 * a * c))

80 g = d / e

90 h = f / e

100 PRINT

105 PRINT “Result of positive x is “; g

110 PRINT “Result for negative x is “; h

115 END

CODING A GAME GUESS PROGRAM ON QBASIC

11. Write a program to play a game of knowing how many days are there in a week?

Solution:

CLS

Score = 0

PRINT “How many days are there in a week?”

INPUT a

IF a = 7 THEN GOTO 2

PRINT “Wrong answer!”

PRINT “To try again – press ‘y’”

INPUT a$

IF a$ = “y” THEN GOTO 1 ELSE END

Score 10

PRINT “It’s the right answer!”

PRINT “Your Score is now”; Score; “!”

PRINT “Thanks for playing”

END

CODING A RECTANGLE MEASUREMENT ON QBASIC

12. Given that:

5cm

6cm

Write a program to calculate the area of the rectangle drawn above

Solution:

REM – Example 5.6

‘ -------------------------------------------------------------

‘ Compute the area of a rectangle

‘ Length L and width W

‘ --------------------------------------------------------------

DIM L AS SINGLE

DIM W AS SINGLE

DIM Area AS SINGLE

CLS

INPUT “Length of the rectangle is “; L

INPUT “Width of the rectangle is “; W

Area = L * W

PRINT “The area of “; L; “by”; W; “rectangle will be “; Area

END

USING BUSINESS / SMALL SCALE FIRM INCENTIVE TO CODE QBASIC

13. You have a Canteen Business and you want to create an incentive bonus for your staff that meet the stipulated target. Write a program that illustrate these statement.

Solution:

REM – Program to set Canteen target

CLS

INPUT “Target “; Target

INPUT “Canteen Sales”; Canteensales

IF Canteensales >= target THEN

Performance$ = “We are Happy”

Bonus = 100 + 0.01 * (canteensales – target)

ELSE

Performance$ = “We are NOT Happy”

Bonus = 0

ENDIF

PRINT “*=============================*”

PRINT “Target”; Target

PRINT “Sales”; Canteensales

PRINT “Performance”; Performance$

PRINT “Bonus”; Bonus

14. Alternatively, the Canteen management held meeting and agreed that where the incentive to the staff does not meet the target, there will be redundancy. Re-write the program to show the decision of the management.

Solution:

REM – Canteen Management Incentive

CLS

INPUT “Target “; Target

INPUT “Sales”; Canteensales

IF Canteensales >= 2 * target THEN

Performance = “Excellent”

Bonus = 1000

ELSEIF Canteensales >= 1.5 * target THEN

Performance$ = “Fine”

Bonus = 500

ELSEIF Canteensales >= target THEN

Performance$ = “Satisfactory”

Bonus = 100

ELSE

Performance$ = “Unsatisfactory”

PRINT “You’re FIRED!!!”

ENDIF

PRINT “Target”; Target

PRINT “Sales”; Canteensales

PRINT “Performance”; Performance$

PRINT “Bonus”; Bonus

15. Write a program to select days of the week within seven days.

Solution:

CLS

INPUT “Date Number is “; dayNumber

SELECT CASE dayNumber

CASE 1

PRINT “Monday”

CASE 2

PRINT “Tuesday”

CASE 3

PRINT “Wednesday”

CASE 4

PRINT “Thursday”

CASE 5

PRINT “Friday”

CASE 6

PRINT “Saturday”

CASE 7

PRINT “Sunday”

CASE ELSE

PRINT “How many days in your week?”

END SELECT

MATHEMATICAL EXPRESSION

16. Write a programme that will show a list of times table number of 3’s e.g. 3 x 1 = 3, 3 x 2 = 6, etc.

Solution:

5 CLS

10 REM – Compute times table numbers of 3

15 INPUT “Enter any number for “; n

20 FOR I = 1 to 12

25 PRINT n; “x”; I “=” n * I

30 NEXT I

35 END

17. Write a program that generates multiples of 5 between 5 and 500, displaying their sum and products at the output screen.

Solution:

5 CLS

10 REM – Program to generate multiples of 5

15 ‘ between 5 and 500

20 ‘ Calculates their sum and products

30 ‘ displayed their results

40 SUM = 0

50 PRDT = 1

60 FOR L = 5 TO 500 STEP 5

70 SUM = SUM + L

80 PRDT = PRDT * L

85 ‘ Display the current values of L, SUM AND PRDT

90 PRINT L, SUM, PRDT

100 NEXT L

110 ‘ display the final values of L, SUM and PRDT

120 PRINT L, SUM, PRDT

130 END

18. Given the below arithmetic sequences:

Find the sum of 12 terms of the series:

7 + 11 + 15 + …

Hence, the first term a = 7, common difference d = 4 and number of terms n = 12.

Requirement:

Use QBASIC to write the above sequences and display the sum of the series at the output.

Solution:

REM Arithmetic sequences

CLS

PRINT “Enter first term”

INPUT A

PRINT “Enter common difference”

INPUT D

PRINT “Enter number of terms”

INPUT N

PRINT “The sequence is “

T = A

S = O

FOR I% = 1 TO N

S = S + T

T = T + D

NEXT I%

PRINT T

PRINT “The sum is “; S

END

CODING BANKING INTEREST/PENSION ADVANCE PAYMENT ON QBASIC

19. Given that the goal you set for your retirement in your current employer is N850,000. You decide to make deposit of your pension payment in advance to ECO BANK PLC with payment of N1,000 each month with the interest of 5.0% interest charge. Write a program to illustrate the above comments, showing the number of years it will take to complete the retirement task.

Solution:

CLS

REM – Program to meet pension retirement goal

DIM Goal AS DOUBLE

DIM Interest AS DOUBLE

DIM Payment AS DOUBLE

DIM Years AS INTEGER

Dim Balance AS DOUBLE

Balance = 0

PRINT “So you want to put some money aside for retirement, hmmmm.”

INPUT “How much money do you need to retire”; Goal

INPUT “How much money will you contribute every year”; Payment

INPUT “Interest rate in % (e.g. use 5.0 for 5.0%) will be”; Interest

Interest = Interest / 100

Balance = Payment

DO WHILE Balance < Goal

Balance = Balance * ( 1 + Interest)

Years = Years + 1

LOOP

PRINT “You can retire in “; Years; “years”

PRINT “with”; Balance; “in the ECO BANK”

END

CODING A MENU LIST FOR CHOICE IN QBASIC

20. Write a menu list program that allow the user to make a wish/choice in a statistical analysis coding system.

Solution:

CLS

PRINT “Which Statistical Analysis do you wish”

PRINT “1. Compute an Average”

PRINT “2. Compute a Standard Deviation”

PRINT “3. Find the Median”

PRINT “4. Find the Smallest and Largest data value”

PRINT “5. Plot the Data”

PRINT “0. Quit/Return to preview menu”

INPUT “Enter your choice ( 0 through 5)”; a%

‘ Use SELECT CASE or IF to check the user

‘ Input, and do the work that has been requested.

LOOP UNTIL a% = 0

MATHEMATICAL CONTINUES

21. Suppose we are given ten rectangles and required to find the area of each rectangle. Given below is a QBASIC program that reads the length and breath of each rectangle, finds its area and prints the areas.

Solution:

5 CLS

10 REM – Program that reads the length “L” and

15 ‘ breath “B” of ten rectangles

20 ‘ calculates the area of each rectangle

30 ‘ and prints the result

40 KANTER = 0

50 PRINT “Please enter the values of L and B”

60 INPUT L

65 INPUT B

70 Area = L * B

80 PRINT L, B, Area

90 KANTER = KANTER + 1

100 IF KANTER > 10 THEN 120

110 GOTO 50

120 END

DATA:

6 X 5cm, 3 X 4cm, 16 X 6cm, 4 X 5cm, 6 X 8cm, 7 X 3cm, 10 X 4cm, 2 X 2cm, 9 X 2cm, 12 X 6cm.

22. Given that you are required to calculate the powers of numbers. Write a programme that list all the resulting powers of an integer that is less than 1000.

For example:

2⁰ = 2, 2¹ = 2, 2² = 4, 2³ = 8, 2⁴ = 16, 2⁵ = 32, 2⁶ = 64, 2⁷ = 128, 2⁸ = 256, 2⁹ = 512, etc.

Solution:

CLS

REM Compute List of powers

Const Maxpower = 1000

DIM Power AS INTEGER

DIM n AS INTEGER

Power = 1 ‘ The first power n ^ 0 is always 1

COLOR 10, 1

PRINT “This program prints all powers <”; Maxpower; “of an integer”

INPUT “Enter an integer for”; n

DO WHILE Power < Maxpower

PRINT Power;

Power = Power * n

LOOP

CODING ACCOUNTING RECORDS ON QBASIC

23. Below is the record of Sales on tickets from each gate of a sports stadium represented as a set of data in the following form:

i) Identity of the gate as G01

ii) Series of positive integers representing the income from the sales of ticket at the gate

Sample Records

G01 27.00 254.00 15.00 21.00

G02 2.00 196.00 240.00

G03 25.00 300.00 10.00

G04 36.00 298.00 150.00 etc

Write a QBASIC programme to read the sample data above, calculate the total income for each gate separately and calculate the total income for the stadium and the gate which records the largest income.

Solution:

5 REM Clear the screen

10 CLS

15 REM Enter the number of the gates that are available

30 INPUT “Enter the number of the gates”; P

35 DIM A$(P), S(P)

40 CLS’

50 FOR K = 1 TO P

60 INPUT “Please enter gate identity”; A$(I)

65 REM Initialize S(I) which represents total income

70 S(I) = 0

80 INPUT “Income from the gate : = “; C

85 REM Test for the negative income which is the terminator

90 IF C > 0 THEN

95 REM Add up the income for each gate

100 S(I) = S(I) + C

105 REM Pass the control to line 80

110 GOTO 80

115 REM Close the if statement

117 ELSE

119 GOTO 130

120 ENDIF

130 CLS

140 NEXT K

150 CLS

155 REM Create a for, next loop to print out the report

160 PRINT “Gate ID. Total Income”

180 FOR I = 1 TO P

190 PRINT A$(I),,, S(I)

210 NEXT I

215 REM Test for the gate with the largest income

217 LG = 0

220 FOR N = 1 TO P

230 IF S(I) > LG THEN

240 LG = S(I)

250 T$ = A$(I)

260 ENDIF

270 NEXT N

275 REM Print the gate with the largest income and the amount

290 PRINT “The gate with the largest income”; LG, “is”; T$

320 END

24. Write QBASIC Program to read the records/accounts of 1000 employees of STARBLISS (NIG.) LTD. Each record has the following layout:

Columns 1 – 20 contains employee surname,

Columns 21 – 35 contains employee other names,

Columns 36 – 45 contains employee department,

Columns 46 – 52 contains employee gross monthly income

Columns 53 – 54 contains spaces,

Columns 54 – 61 contains employee gross monthly deduction.

Requirement:

Calculate the total monthly net pay of each employee and generate the output reports and accounts.

Solution:

10 REM This programme reads the records of 1000 employee of

20 ‘ STARBLISS (NIG.) LTD. Each employee is described by

30 ‘ surname, other names, departments,

40 ‘ gross monthly income and gross monthly deduction.

50 ‘ Calculate for each employee

60 ‘ the total gross income

65 ‘ the total gross deduction and

70 ‘ monthly net pay and print the output report

90 CLS

100 REM Set all previous key setting off

110 KEY OFF

120 DIM S$(1000), O$(1000), T$(1000), M(1000), U(1000), N(1000)

130 TINC = 0

140 TDED = 0

150 TNCTPAY = 0

160 REM Set a for and next loop to accept 1000 records

170 FOR I = 1 TO 1000

180 REM accept all the necessary data

190 INPUT “Surname: “; S$(I)

200 INPUT “Other names: “; O$(I)

210 INPUT “Department: “; T$(I)

220 INPUT “Gross monthly income: “; M(I)

230 INPUT “Gross monthly deduction: “; U(I)

240 REM Calculate monthly net pay for each employee

250 N(I) = M(I) – U(I)

260 TINC = TINC + M(I)

270 TDED = TDED + U(I)

280 TNETPAY = TNETPAY + N(I)

290 CLS

300 NEXT I

310 CLS

320 REM Print the required report

330 FOR I = 1 TO 1000

340 PRINT S$(I), O$(I), T$(I), M(I), U(I), N(I)

350 NEXT I

360 REM Print total gross income, total gross deduction and total net pay

370 PRINT “Total gross income: “; TINC

380 PRINT “Total gross deduction: “; TDED

390 PRINT “Total net pay: “; TNETPAY

400 END

25. Write QBASIC Programme to input the records of a file where each record contains the identity of a person, the amount of loan in Naira he obtains (the principal), the interest rate of the loan and the number of payment period per year. The programme should compute the loan payment required for each pay period to repay the outstanding principal in one year at the indicated rate in Naira equal payments. The formula for calculating payments is:

Payment = P(1 + K) + 12

Where

P = Principal loan

K = Interest rate

n = Number of periods per year

Solution:

10 CLS

20 REM Set previous key setting off

30 KEY OFF

40 REM Enter the number of the debtors

50 INPUT “Please enter the number of debtors to consider”; d

60 CLS

70 DIM A$(d), B$(d), C(d), D(d), E(d), F(d)

80 REM Create a for and next loop to accept the records of debtors

90 FOR I = 1 TO d

100 INPUT “Surname: “; A$(I)

110 INPUT “Other names: “; B$(I)

120 INPUT “Principal Loan: “; C(I)

130 INPUT “Interest rate: “; K(I)

140 INPUT “Payment period per year = “; E(I)

150 REM Compute the payment per period for each debtor

160 F(I) = (C(I) * (1 + K(I)) + 12) / E(I)

170 CLS

180 NEXT I

190 CLS

200 REM Print the report

210 FOR I = 1 TO d

220 PRINT A$(I), B$(I), C(I), K(I), E(I), F(I)

225 NEXT I

230 END

INTRODUCING BASIC GRAPHICS ON QBASIC

26. Write QBASIC programme that causes a red “lighting bolt” to be displayed on the screen

Solution:

10 REM Case study of lighting bolt

20 REM

30 KEY OFF

35 CLS

40 SCREEN 1

45 COLOR 0,0

50 LINE (20, 20) – (120, 80), 2

55 LINE – (80, 80), 2

60 LINE – (220, 180), 2

65 LINE – (140, 100), 2

70 LINE – (190, 100), 2

80 LINE – (110, 20), 2

90 LINE – (20, 20), 2

100 END

27. Given below is a QBASIC Programme which causes a sequence of rectangles to move from the centre of the screen to the outer edges. This programme also utilizes sound to enhance the graphics effects.

Solution:

10 REM Case study of concentric rectangles

20 REM

30 KEY OFF

35 CLS

40 SCREEN 1

45 COLOR 0, 1

47 C = 3

50 P = 0

55 Q = -45

70 REM Begin main loop

80 FOR I = 1 TO 10

90 LINE (160 – 1.6 * P, 100 – P) – (160 + 1.6 * P, 100 + P), C, B

100 IF Q > 0 THEN

105 LINE (160 – 1.6 * Q, 100 – Q) – (160 + 1.6 * Q, 100 + Q), O, B

107 ENDIF

110 P = P + S

115 IF P > 95 THEN

117 P = 0

119 C = 1 + INT(3 * RND)

120 Q = Q + 5

123 ENDIF

125 IF Q > 95 THEN

127 Q = 0

129 ENDIF

130 IF P = 0 OR Q = 0 THEN

133 SOUND 20 + INT(100 * RND), 10

135 ENDIF

140 NEXT I

150 END

28. Given below is a QBASIC programme which causes repeated groups of concentric circles to be generated, with each group starting at the centre of the screen and moving outward to the edge.

Solution:

10 REM Case study of concentric circles

20 REM

30 KEY OFF

35 CLS

40 SCREEN 1

45 COLOR 0, 1

50 LINE (39, 0) – (279, 199), 3B

60 CLR = 1

70 REM

80 REM begin loop

90 REM

100 FOR 1 = 5 TO 120 STEP 5

110 CIRCLE (160, 100), R, CLR

120 NEXT I

130 CLR = CLR + I

133 IF CLR > 3 THEN

135 CLR = 1

137 ENDIF

140 GOTO 100

150 END

29. Write an alternative QBASIC programme that allow any shape objects, circles, ellipses and rectangles to be filled with other paint colours, with the general form of using paint statement.

Solution:

5 CLS

10 REM This programme generates concentric painted circles

20 SCREEN 9

30 FOR K = 1 TO 100

40 CIRCLE(300, 165), K

50 CIRCLE(320, 165), K

60 CIRCLE(100, 183), K

70 CIRCLE(200, 265), K

80 CIRCLE(220, 34), K

90 CIRCLE(240, 55), K

100 CIRCLE(120, 134), K

110 CIRCLE(160, 123), K

120 CIRCLE(80, 265), K

130 CIRCLE(40, 80), K

140 CIRCLE(14, 105), K

150 CIRCLE(140, 25), K

160 CIRCLE(70, 65), K

170 CIRCLE(300, 16), K

180 CIRCLE(400, 84), K

190 CIRCLE(340, 99), K

200 LINE (500, 200 – K + 8) – (600, 230 – K + 8), 2, BF

210 LINE (350, 225 – K + 8) – (500, 215 – K + 8), 7, BF

220 SLEEP 1

230 LINE (500, 200 – K + 8) – (600, 230 – K + 8), 0, BF

240 LINE (350, 225 – K + 8) – (500, 215 – K + 8), 0, BF

250 NEXT K

260 END

ADVANCE GRAPHS OF BAR CHART ON QBASIC

30. Given below is a QBASIC programme that causes a bar chart to be generated. Each value is assumed to be non-negative, therefore the values will be displayed above each of their respective rectangles, that is, above each “bar”

To run the programme, the input data set are:-

Annual Sales Increases

Increase (%) Year

7.8 1991

8.2 1992

6.7 1993

10.6 1994

12.3 1995

Solution:

10 REM Bar chart generation

20 REM

30 KEY OFF

35 CLS

40 WIDTH 80

42 SCREEN 0

44 COLOR 7, 0

50 DIM Label$(12), Y(12)

60 LOCATE 1, 20: PRINT String$(40, “*”)

70 LOCATE 2, 20: PRINT “*”; SPC(38); “*”

80 LOCATE 3, 20: PRINT “*”; SPC(9); “Bar Chart Generation”; SPC(10); “*”

90 LOCATE 4, 20: PRINT “*”; SPC(38); “*”)

100 LOCATE 5, 20: PRINT String$(40, “*”)

110 YMAX = 0

120 REM

130 REM Enter data and find largest y

140 REM

150 LOCATE 7, 1: INPUT “Title: “; Title$

160 LOCATE 9, 1: INPUT “How many data items? (1 – 12)”; ANS$

165 N = VAL(ANS$)

170 IF N < 1 OR N > 12 THEN

173 BEEP

175 LOCATE 9, 29: PRINT Space$(6)

177 ENDIF

179 GOTO 160

180 FOR I = 1 TO N

190 LOCATE 1 + 10: PRINT “I = “; I

200 LOCATE 1 + 10, 15: INPUT “Value: “; ANS$

205 Y(I) = VAL(ANS$)

210 IF LEFT$(ANS$, 1) = “0” THEN 230

220 IF Y(I) < = 0 THEN

222 BEEP

224 LOCATE 1 + 10, 21: PRINT Space$(6)

226 ENDIF

228 GOTO 200

230 LOCATE 1 + 10, 35: INPUT “Label: “; Label$(I)

240 IF Y(I) > YMAX THEN YMAX = Y(I)

250 NEXT I

260 REM

270 REM Generate and display the bar chart

280 REM

290 CLS

292 W = 60 \ N

300 FOR I = 1 TO N

310 R = 20 – 18 * Y(I) \ YMAX

313 IF R = 20 THAN 370

320 FOR ROW = R TO 20

330 FOR COL = ( I – 1) * W + 11 TO I * W + 8

340 LOCATE ROW, COL: PRINT “*”

350 NEXT COL

360 NEXT ROW

370 NEXT I

380 REM

390 REM Label the bar chart

400 REM

410 FOR I = 1 TO N

420 R = 19 – 19 * Y(I) \ YMAX

430 C = 9 + (I – 1) * W + (W – LEN(Str$(Y(I) ) ) ) / 2

440 LOCATE R, C: PRINT Y(I)

450 C = 10 + (I – 1) * W + (W – LEN (Label$(I) ) ) / 2

460 LOCATE 21, C: PRINT Label$ (I)

470 NEXT I

480 C = 10 + (N * W – LEN(Title$) ) / 2

490 LOCATE 23, C: PRINT Title$; :LOCATE 23, 1

500 END

ANIMATIONS OF GRAPHICS ON QBASIC

31. Given below is a basic programme which causes a ball to move freely within a confined enclosure. Write to generate the animation by means of the GET and PUT statement.

Solution:

10 REM Bouncing Ball

20 REM

30 KEY OFF

35 CLS

40 DEFINT A – Z

50 RANDOMIZE

55 CLS

60 SCREEN 2

70 DIM BALL (34)

80 LINE (0, 0) – (639, 199), , B

90 LINE (10, 5) – (629, 194), , B

100 PAINT (5, 2)

110 X = 20 + INT(600 * RND)

115 Y = 20 + INT(190 * RND)

120 DX = 1 + INT(10 * RND)

125 DY = 1 + INT(10 * RND)

130 CIRCLE (X, Y), 10

140 PAINT (X, Y)

150 GET(X – 10, Y – 10) – (X + 10, Y + 10), BALL

190 PUT(X – 1 – , Y – 10), BALL

200 X1 = X + DX

205 Y1 = Y + DY

210 IF X1 < 21 THEN

213 X1 = 21

215 DX = -DX

217 ENDIF

219 GOTO 230

223 X1 = 618

225 DX = -DX

227 ENDIF

230 IF Y1 < 10 THEN

233 Y1 = 10

235 DY = -DU

237 ENDIF

239 GOTO 250

240 IF Y1 > 189 THAN

243 Y1 = 189

245 DY = -DY

247 ENDIF

250 PUT(X1 – 10, Y1 – 10), BALL

260 X = X1

265 Y = Y1

270 FOR K = 1 TO 5

275 NEXT K

280 GOTO 190

290 END

ADVANCE ANIMATION

32. Write a QBASIC program of moving circular shape objects.

Solution:

10 REM This program makes a particular shape

20 REM scrolls up the screen leaving a circular design

30 CLS

40 SCREEN 1

50 FOR K = 1 TO 300 STEP 10

60 LINE(50, 120 – K) – (100, 300 – K), 2, BF

70 LINE(100, 70 – K) – (200, 300 – K), , BF

80 LINE(150, 120 – K) – (250, 300 – K), 2, BF

90 SLEEP 1

100 LINE(50, 120 – K) – (100, 300 – K), 0, BF

110 LINE(100, 70 – K) – (200, 300 – K), 0, BF

120 LINE (150, 120 – K) – (250, 300 – K), 0, BF

130 CIRCLE(150, 150), K, 1

140 NEXT K

33. Write QBASIC program that display a picture of human face using object.

Solution:

5 CLS

10 REM This programme displays the picture of a human face

20 SCREEN 1

30 FOR K = 1 TO 10

40 COLOR 7, 2

50 CIRCLE(150, 100), 70

60 CIRCLE(120, 80), K

70 CIRCLE(180, 80), K

80 LINE(150, 80) – (170, 110)

90 LINE-(150, 110 – K)

100 CIRCLE(150, 130), K

110 SLEEP 1

120 NEXT K

34. Write a QBASIC programme that generate a waving Nigerian flag on a pole using objects.

Solution:

5 CLS

10 REM This program generates Nigerian flag on a pole

20 SCREEN 9

30 FOR K = 1 TO 100

40 LINE(150, 100) – (200, 140), 2, BF

50 LINE(200, 100) – (250, 140), 7, BF

60 LINE(250, 100) – (310, 140), 2, BF

70 LINE(300, 100) – (310, 300), 1, BF

80 SLEEP 1

90 LINE(150, 100) – (200, 140), 0, BF

100 LINE(200, 100) – (250, 140), 0. BF

110 LINE(250, 100) – (300, 140), 0, BF

120 LINE(300, 100) – (310, 300), 1, BF

130 LINE(310, 100) – (360, 140), 2, BF

140 LINE(360, 100) – (410, 140), 7. NF

150 LINE(140, 100) – (460, 140), 2, BF

160 LINE(300, 100) – (310, 300), 1, BF

170 SLEEP 1

180 LINE(310, 100) – (360, 140), 0, BF

190 LINE(360, 100) – (410, 140), 0, BF

200 LINE(410, 100) – (460, 140), 0, BF

210 LINE(300, 100) – (310, 300), 1, BF

220 NEXT K

OPTIONAL

APPENDIX A: (CASE STUDY OF A RACING CAR)

35. Write QBASIC programme that generates a racing car using objects

Solution:

43 CLS

44 REM This programme generates a racing car

45 SCREEN 1

46 COLOR 2

47 LINE(10 + K, 100 + J) – (10 + K, 80 + J)

48 LINE –(30 + K, 80 + K)

49 LINE –(50 + K, 60 + J)

50 LINE –(70 + K, 57 + J)

51 LINE –(90 + K, 60 + J)

52 LINE –(120 + K, 80 + J)

53 LINE –(170 + K, 80 + J)

54 LINE –(180 + K, 100 + J)

55 LINE –(180 + K, 110 + J)

56 LINE –(170 + K, 110 + J)

57 LINE(10 + K, 100 + J) – (20 + K, 110 + J)

58 LINE(65 + K, 110 + J) – (140 + K, 110 + J)

59 LINE(10 + K, 100 + J) – (35 + K, 100 + J)

60 LINE(60 + K, 100 + J) – (140 + K, 100 + J)

61 LINE(180 + K, 100 + J) – (170 + K, 100 + J)

62 LINE(10 + K, 90 + J) – (170 + K, 90 + J)

63 LINE(70 + K, 80 + J) – (80 + K, 90 + J)

64 LINE –(80 + K, 110 + J)

65 LINE(120 + K, 80 + J) – (130 + K, 90 + J)

66 LINE –(130 + K, 110 + J)

67 LINE(50 + K, 80 + J) – (50 + K, 95 + J)

68 LINE(77 + K, 82 + J) – (80 + K, 85 + J), 5, BF

69 LINE(52 + K, 82 + J) – (55 + K, 85 + J), 5, BF

70 LINE(50 + K, 80 + J) – (50 + K, 60 + J)

71 LINE –(90 + K, 60 + J)

72 LINE(30 + K, 80 + J) – (120 + K, 80 + J)

73 LINE(52 + K, 62 + J) – (69 + K, 78 + J), 3, BF

74 LINE(71 + K, 62 + J) – (88 + K, 78 + J), 3, BF

75 LINE(90 + K, 62 + J) – (118 + K, 78 + J)

76 LINE –(90 + K, 78 + J)

77 LINE –(90 + K, 62 + J)

78 LINE(70 + K, 80 + J) – (80 + K, 90 + J)

79 CIRCLE(50 + K, 110 + J), 15

80 CIRCLE(50 + K, 110 + J), 10

81 LINE(40 + K, 110 + J) – (60 + K, 110 + J)

82 LINE(50 + K, 105 + J) – (50 + K, 115 + J)

83 CIRCLE(155 + K, 110 + J), 15

84 CIRCLE(155 + K, 110 + J), 10

85 LINE(145 + K, 110 + J) – (165 + K, 110 + J)

86 LINE(155 + K, 105 + J) – (155 + K, 115 + J)

87 LINE(20 + K, 110 + J) – (35 + K, 110 + J)

88 PRINT “Set! … “; BEEP

89 SLEEP 3

90 LOCATE 10, 30: PRINT “Go! …”; BEEP

91 SLEEP 1

92 CLS

93 SCREEN 9

94 COLOR 2

95 FOR T = 1 TO 5

96 LINE (1, 50) – (700, 140), , B

97 LINE (1, 230) – (700, 230)

98 LINE (1, 320) – (700, 320)

99 FOR J = 1 TO 270 STEP 90

100 FOR K = 1 TO 1000 STEP 50

101 LINE (10 + K, 100 + J) – (10 + K, 80 + J)

102 LINE –(30 + K, 80 + J)

103 LINE –(50 + K, 60 + J)

104 LINE –(70 + K, 57 + J)

105 LINE –(90 + K, 60 + J)

106 LINE –(120 + K, 80 + J)

107 LINE –(170 + K 90 + J)

108 LINE –(180 + K, 100 + J)

109 LINE –(180 + K, 110 + J)

110 LINE –(170 + K, 110 + J)

120 LINE (10 + K, 100 + J) – (20 + K, 110 + J)

130 LINE (65 + K, 110 + J) – (140 + K, 110 + J)

140 LINE (10 + K, 100 + J) – (35 + K, 100 + J)

150 LINE (60 + K, 100 + J) – (140 + K, 100 + J)

160 LINE (180 + K, 100 + J) – (170 + K, 100 + J)

170 LINE (10 + K, 90 + J) – (170 + K, 90 + J)

180 LINE (70 + K, 80 + J) – (80 + K, 90 + J)

190 LINE –(80 + K, 110 + J)

200 LINE (120 + K, 80 + J) – (130 + K, 90 + J)

210 LINE –(130 + K, 110 + J)

220 LINE (50 + K, 80 + J) – (50 + K, 95 + J)

230 LINE (77 + K, 82 + J) – (80 + K, 85 + J), 5, BF

240 LINE(52 + K, 82 + J) – (55 + K, 85 + J), 5, BF

250 LINE (50 + K, 80 + J) – (50 + K, 60 + J)

260 LINE –(90 + K, 60 + J)

270 LINE (30 + K, 80 + J) – (120 + K, 80 + J)

280 LINE(52 + K, 62 + J) – (69 + K, 78 + J), 3, BF

290 LINE(71 + K, 62 + J) – (88 + K, 78 + J), 3, BF

295 LINE (90 + K, 62 + J) – (88 + K, 78 + J)

300 LINE –(90 + K, 78 + J)

310 LINE –(90 + K, 62 + J)

320 LINE (70 + K, 80 + J) – (80 + K, 90 + J)

330 CIRCLE (50 + K, 110 + J), 15

340 CIRCLE (50 + K, 110 + J), 10

350 LINE (40 + K, 110 + J) – (60 + K, 110 + J)

360 LINE (50 + K, 105 + J) – (50 + K, 115 + J)

370 CIRCLE (155 + K, 110 + J), 15

380 CIRCLE (155 + K, 110 + J), 10

390 LINE (145 + K, 110 + J) – (165 + K, 110 + J)

400 LINE (155 + K, 105 + J) – (155 + K, 115 + J)

410 LINE (20 + K, 110 + J) – (35 + K, 110 + J)

420 LINE (10 + K, 100 + J) – (10 + K, 80 + J), 0

430 LINE –(30 + K, 80 + J), 0

440 LINE –(50 + K, 60 + J), 0

450 LINE –(70 + K, 57 + J), 0

460 LINE –(90 + K, 60 + J), 0

470 LINE –(120 + K, 80 + J), 0

480 LINE –(170 + K, 90 + J), 0

490 LINE –(180 + K, 100 + J), 0

500 LINE –(180 + K, 110 + J), 0

510 LINE –(170 + K, 110 + J), 0

520 LINE (10 + K, 100 + J) – (20 + K, 110 + J), 0

530 LINE (65 + K, 110 + J) – (140 + K, 110 + J), 0

540 LINE (10 + K, 100 + J) – (35 + K, 100 + J), 0

550 LINE (60 + K, 100 + J) – (140 + K, 100 + J), 0

560 LINE (180 + K, 100 + J) – (170 + K, 100 + J), 0

570 LINE (10 + K, 90 + J) – (170 + K, 90 + J), 0

580 LINE (70 + K, 80 + J) – (80 + K, 90 + J), 0

590 LINE –(80 + K, 110 + J), 0

600 LINE (120 + K, 80 + J) – (130 + K, 90 + J), 0

610 LINE –(130 + K, 110 + J), 0

620 LINE (50 + K, 80 + J) – (50 + K, 95 + J), 0

630 LINE (77 + K, 82 + J) – (80 + K, 85 + J), 0, BF

640 LINE (52 + K, 82 + J) – (55 + K, 85 + J), 0, BF

650 LINE (50 + K, 80 + J) – (50 + K, 60 + J), 0

660 LINE –(90 + K, 90 + J), 0

670 LINE (30 + K, 80 + J) – (120 + K, 80 + J), 0

680 LINE (52 + K, 62 + J) – (80 + K, 85 + J), 0, BF

690 LINE (71 + K, 62 + J) – (88 + K, 78 + J), 0, BF

700 LINE (90 + K, 62 + J) – (118 + K, 78 + J), 0

710 LINE –(90 + K, 78 + J), 0

720 LINE –(90 + K, 62 + J), 0

730 LINE (70 + K, 80 + J) – (80 + K, 90 + J), 0

740 CIRCLE (50 + K, 110 + J), 15

750 CIRCLE (50 + K, 110 + J), 10

760 LINE (40 + K, 110 + J) – (60 + K, 110 + J), 0

770 LINE (50 + K, 105 + J) – (50 + K, 115 + J), 0

780 CIRCLE (155 + K, 110 + J), 15, 0

790 CIRCLE (155 + K, 110 + J), 10, 0

800 LINE (145 + K, 110 + J) – (165 + K, 110 + J), 0

810 LINE (155 + K, 105 + J) – (155 + K, 115 + J), 0

820 LINE (20 + K, 110 + J) – (35 + K, 110 + J), 0

830 NEXT K

840 NEXT J

850 NEXT T

I WILL STOP HERE FOR NOW. I HOPE THIS WILL HELP YOU FOR YOUR PROGRAMMING.

THANKS AND GOD BLESS YOU.

INTRODUCTION TO COMPUTER PROGAMMING IN QBASIC LANGUAGE

Tuesday 19 March 2013

INTRODUCTION TO COMPUTER PROGAMMING IN QBASIC LANGUAGE

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