View
669
Download
3
Category
Tags:
Preview:
Citation preview
BASICIncludes Visual BASIC, VB.net, QuickBasic,
PowerBasic, GW Basic, PowerBASIC and the
BASIC Programming Language
Shane Estavillo
Jeffrey James Valerio
BASICeginner
’sll Purposeymbolic
nstructionode
It is a family of high-level programming languages, in other words, a multi
platform language.
One of the earliest and simplest high-level languages with commands
similar to English. It can be learned with relative ease even by
schoolchildren and novice programmers.
It is in widespread use but has gotten little respect.
BASIC
The language was based partly on the FORTRAN IV and partly on the ALGOL 60, with additions to make it suitable for timesharing.
FORTRAN IV (1962)
ALGOL 60 (1960
BASIC (1964)
Genealogy of BASIC
The language was based partly on the FORTRAN IV and partly on the ALGOL 60, with additions to make it suitable for timesharing.
BASIC
(1964)
QuickBASIC(1988)
Visual BASIC (1990)
Original BASIC Language
OverviewVery small and oddly, was not interactive.
No means of getting input data from terminal.
Programs were typed in, compiled and run, in sort of batch-oriented way.
Had only 14 different statement types and a single data type, floating point, referred to as “numbers”.
Overall, it was very limited language though quite easy to learn.
Significant Language
Features
Loops
Input from the keyboard
Menu Driven Applications
System Commands - These are words
that make the system perform a
specific task immediately.
Significant Language
FeaturesUser-Defined Functions
Arrays, sorting, and searches
Areas of Application
BASIC has many strong points, such as:
Easy to learn for beginners
Structured Programming
Subroutines
Built-In Functions
Significant Language
FeaturesAdds powerful additional features for
the advanced user
Is designed for interactive use rather
than batch work
Lends itself to learning by hands-on
practical use
and is therefore suitable for both the
professional and non-professional.
The goals of the system were:
1. It must be easy for non-science
students to learn and use.
2. It must be pleasant and friendly.
3. It must provide fast turnaround for
homework.
4. It must allow free and private access.
5. It must consider user time more
important than computer time.
The eight design principle of
BASIC:1. Be easy for beginners to use.
2. Be a general-purpose programming language.
3. Allow advanced features to be added for experts (while keeping the language simple for beginners).
4. Be interactive.
5. Provide clear and friendly error messages.
6. Respond quickly for small programs.
7. Not to require an understanding of computer hardware.
8. Shield the user from the operating system.
Evaluation and Criticisms
Poor structure of programs written in it.
Early versions were not meant for serious programs of any significant size, though later versions can handle such tasks.
Edsger W. Djikstra, a highly-respected computer proffessional that the use of GoTo statements, particularly in BASIC, promoted poor programming practices.
BASIC is too slow.
Then why BASIC is
successful?Ease with which it can be learned and
the ease with which it can be
implemented, even on very small
computers.
The original
BASIC was
designed in 1964
by John George
Kemeny (right)
and Thomas
Eugene Kurtz
(left) at Dartmouth
College (now
Dartmouth
University) in New
Hampshire, USA
Brief History of BASIC
Before the mid-1960s, computers were extremely expensive and used only for special-purpose tasks.
As prices decreased, from research aabs, computing went into commercial use.
Newer computer systems then supportedtime-sharing, a system that allows multiple users or processes to use the CPU and memory.
Brief History of BASIC
In the following years, as other dialects of BASIC appeared, Kemeny and Kurtz’s original BASIC dialect became known as Dartmouth BASIC.
When it was implemented in minicomputers DEC PDP Series and the Data General Nova; HP-Time Shared BASIC System (1960s), BASIC acted merely as an interpreter rather than a compiler.
Brief History of BASIC
It was the introduction of Altair 8800
“kit” microcomputer in 1975 that
provided BASIC a path to
universality.
BASIC provided faster memory
access for audio tapes and suitable
text editors that time.
Brief History of BASIC
In order to promote the language, it
was available FREE OF CHARGE.
One of the first to appear was the Tiny
Basic originally written by Li-Chen
Wang, a simple BASIC
implementation. For 8080 machines
like the Altair.
Brief History of BASIC
MITS then released Altair BASIC,
developed by Bill Gates and Paul
Allen in 1975.
Microsoft BASIC (widely known as
MBASIC or M BASIC)was soon
bundled with an original floppy disk
based CP/M computers.
Brief History of BASIC
The Atari 8-bit family had their own
Atari BASIC that was modified in order
to fit on 8 kB ROM cartridge.
The BBC published BBC BASIC,
developed for them by Acorn
Computers Ltd, incorporating many
extra structuring keywords.
Brief History of BASIC
As early as 1979 Microsoft was in
negotiations with IBM to supply them
with a version of BASIC. Microsoft
sold several versions of BASIC for
MS-DOS/ PC-DOS including BASICA,
GW-BASIC (a BASICA-compatible
version that did not need IBM's ROM)
and QuickBASIC.
Brief History of BASIC
Turbo Pascal & Turbo C++-publisher
Borland published Turbo BASIC 1.0 in
1985 (successor versions are still
being marketed by the original author
under the name PowerBASIC).
Brief History of BASIC
These languages introduced many
extensions to the original home
computer BASIC, such as improved
string manipulation and graphics
support, access to the file system and
additional data types. More important
were the facilities for structured
programming, including additional
control structures and proper
subroutines supporting local variables.
The Shift of BASIC into Visual
BASICThe Visual BASIC introduced by
Microsoft is difficult to consider to be
really the original BASIC, since of its
major shift towards being object-
oriented and event-driven in
perspective.
VB Version 3.0 is widely considered
the first relatively stable version.
Basic BASIC Syntax
SYNTAX
TYPICAL BASIC KEYWORDS
Data manipulation
LET: assigns a value (which may be
the result of an expression) to a
variable.
DATA: holds a list of values which are
assigned sequentially using the READ
command.
Program flow control
IF ... THEN ... ELSE: used to perform comparisons or make decisions.
FOR ... TO ... {STEP} ... NEXT: repeat a section of code a given number of times. A variable that acts as a counter is available within the loop.
WHILE ... WEND and REPEAT ... UNTIL: repeat a section of code while the specified condition is true. The condition may be evaluated before each iteration of the loop, or after.
DO ... LOOP {WHILE} or {UNTIL}: repeat a section of code Forever or While/Until the specified condition is true . The condition may be evaluated before each iteration of the loop, or after.
GOTO: jumps to a numbered or labelled line in the program.
Program flow control
GOSUB: jumps to a numbered or labelled line, executes the code it finds there, but upon encountering the RETURN Command, it jumps back to the line following the line from which the jump occurred. This is used to implement subroutines.
ON ... GOTO/GOSUB: chooses where to jump based on the specified conditions. See Switch statement for other forms.
DEF FN: a pair of keywords introduced in the early 1960s to define functions. The original BASIC functions were modelled on FORTRAN single-line functions. BASIC functions were one expression with variable arguments, rather than subroutines, with a syntax on the model of DEF FND(x) = x*x at the beginning of a program. Function names were restricted to FN+oneletter.
I/O: Input and Output
PRINT: displays a message on the
screen or other output device.
INPUT: asks the user to enter the
value of a variable. The statement
may include a prompt message.
TAB or AT: sets the position where the
next character will be shown on the
screen or printed on paper.
Miscellaneous Syntax
REM: holds a programmer's comment or REMark; often used to give a title to the program and to help identify the purpose of a given section of code.
USR: transfers program control to a machine language subroutine, usually entered as an alphanumeric string or in a list of DATA statements.
TRON: turns on a visual, screen representation of the flow of BASIC commands by displaying the number of each command line as it is run. The TRON command, largely obsolete now, stood for, TRace ON. This meant that command line numbers were displayed as the program ran, so that the command lines could be traced. This command allowed easier debugging or correcting of command lines that caused problems in a program.
Miscellaneous Syntax
Problems included a program terminating without providing a desired result, a program providing an obviously erroneous result, a program running in a non-terminating loop, or a program otherwise having a non-obvious error. (The command TRON has also entered popular cultural with the name of the 1982 Disney movie, "TRON," with a subsequent movie, "TRON: Legacy," a television series, "TRON: Uprising," and two video games, "TRON: Legacy," and "TRON:Evolution." In each of these entertainments the TRON command is personified as a character that battles against evil elements in programs.)
TROFF: turns off the display of the number of each command line as command lines run after the command TRON has been used.
DATA TYPES AND VARIABLES
Minimal versions of BASIC had only integer variables and one-letter variable names. More powerful versions had floating-point arithmetic, and variables could be labelled with names six or more characters long.
String variables are usually distinguished in many microcomputer dialects by having $ suffixed to their name, and string values are typically enclosed in quotation marks.
Arrays in BASIC could contain integers, floating point or string variables.
Some dialects of BASIC supported matrices and matrix operations, useful for the solution of sets of simultaneous linear algebraic equations. These dialects would support matrix operations such as assignment, addition, multiplication (of compatible matrix types), and evaluation of a determinant. Microcomputer dialects often lacked this data type and required a programmer to provide subroutines to carry out equvalent operations.
BASIC (PROGRAMMING LANGUAGE) IS AN EARLIER VERSION OF VISUAL BASIC. VB IS MODIFIED FOR PC USER U CAN SAY IT IS A GUI VERSION OF BASIC.
The next set of
discussions are
directly based on
the Original
Manual of the
BASIC
Programming
Language
designed for use
in the Darthmouth
Time-Sharing
System.
BASIC Programming
Unstructured BASIC
These are the first-generation BASIC languages such as MSX BASIC and GW BASIC.
Most support:
Simple Data Types
Loop Cycles
Arrays
Hello World !Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
Hello World! Hello World! Hello World!
10 PRINT "Hello World! "
20 GOTO 10
This program prints the phrase “Hello
World! “ infinitely.
Sample Program for GW
BASIC
10 INPUT "ENTER TWO NUMBERS SEPARATED BY A COMMA:
20 LET S = N1 + N2
30 LET D = N1 - N2
40 LET P = N1 * N2
50 LET Q = N1 / N2
60 PRINT "THE SUM IS ", S
70 PRINT "THE DIFFERENCE IS ", D
80 PRINT "THE PRODUCT IS ", P
90 PRINT "THE QUOTIENT IS ", Q
100 END
Sample Program for GW
BASIC
ENTER TWO NUMBERS SEPARATED BY A COMMA:
THE SUM IS 6
THE DIFFERENCE IS 2
THE PRODUCT IS 8
THE QUOTIENT IS 2
Structured BASIC
Second Generation BASICs are structured and procedure-oriented programming.
Line numbering is omitted and then replaced with labels for GoTo and procedure.
QuickBASIC and PowerBASIC are examples.
BASIC with Object-Oriented
featuresThird generation BASIC dialects such
as Visual Basic and StarOffice Basic
introduced features to support object-
oriented and event-driven
programming paradigm.
Most built-in procedures and functions
now represented as methods of
standard objects rather than operators
.
Visual BASIC
Visual basic is derived form the BASIC programming languages, it is a Microsoft window programming language, visual basic program are created in an integrated development environment (IDE), which allows the programmer to create run and design visual basic programs conveniently it’s also allow a programmer to create working programs in a fraction of time that normally takes to code programs without using IDES.
Visual BASIC
The wide spread use of BASIC Language with various types of computer (sometimes called hardware platform) led to many enhancement to the languages with the development of Microsoft windows graphical user interface (GUI) in the late 1980’s and the early 1990’s, the natural evolution of basic was visual basic which was created by Microsoft corporation in 1991.
Procedural BASIC: True
BASICTrue BASIC, C, Fortran, and Pascal are examples of procedural languages. Procedural languages change the state or memory of the machine by a sequence of statements. True BASIC is similar to F (a subset of Fortran 90) and has excellent graphics capabilities which are hardware independent. True BASIC programs can run without change on computers running the Macintosh, Unix, and Windows operating systems. We will consider version 3.0 (2.7 on the Macintosh) of True BASIC. Version 5 includes the ability to build objects such as buttons, scroll bars, menus, and dialog boxes. However, because we wish to emphasize the similarity between True BASIC and other procedural languages such as C, F, and Java, we do not consider these features.
Procedural BASIC: True
BASICPROGRAM product
! taken from Chapter 2 of Gould & Tobochnik
LET m = 2 ! mass in kilograms
LET a = 4 ! acceleration in mks units
LET force = m*a ! force in Newtons
PRINT force
END
Procedural BASIC: True
BASICThe features of True BASIC included
in the above program include:
The first statement is an optional
PROGRAM header. The inclusion of a
program header is good programming
style.
Procedural BASIC: True
BASICComment statements begin with ! and
can be included anywhere in the
program.
PROGRAM, LET, PRINT, and END
are keywords (words that are part of
the language and cannot be
redefined) and are given in upper
case. The case is insignificant (unlike
C, F, and Java). The DO FORMAT
command converts keywords to upper
case.
Procedural BASIC: True
BASICThe LET statement causes the expression to the right of the = sign to be evaluated and then causes the result to be assigned to the left of the = sign. (The LET statement reminds us that the meaning of the = symbol is not the same as equals.) It is not necessary to type LET, because the DO FORMAT command automatically inserts LET where appropriate. The LET statement can be omitted if the OPTION NOLET statement is included.
Procedural BASIC: True
BASICTrue BASIC does not distinguish between integer numerical variables and floating point numerical variables and recognizes only two types of data: numbers and strings (characters). The first character of a variable must be a letter and the last must not be an underscore.
The PRINT statement displays output on the screen.
The last statement of the program must be END.
Sample True BASIC with
inputPROGRAM product2
INPUT m
INPUT prompt "acceleration a (mks
units) = ": a
LET force = m*a ! force
in Newton's
PRINT "force (in Newtons) ="; force
END
Visual BASIC
Visual basic is the worlds most widely use RAD language, (Rapid Application Development (RAD) is the process of rapidly creating an application. Visual Basic provide a powerful features such as graphical user interface, events handling assess to Win 32 API, object-oriented features, error handling, structured programming and much more. Not until Visual Basic appeared, developing Microsoft windows based application was a difficult and cumbersome process. Visual basic greatly simplifies window application development. The advantages of visual basic programming language
Visual BASIC
VB 1.0 was introduced in 1991. The drag
and drop design for creating the user
interface is derived from a prototype form
generator developed by Alan Cooper and
his company called Tripod. Microsoft
contracted with Cooper and his
associates to develop Tripod into a
programmable form system for Windows
3.0, under the code name Ruby (no
relation to the Ruby programming
language).
Visual BASIC Features
Visual Basic gives a disciplined approach to writing programs that are clearer than unstructured programs, easier to test, debug and can be easily modify.
It allows for the creation of powerful and professional looking application with less time and coding. It allows for strong typing i.e. has wide variety of input data types and support Rapid Application Development (RAD).
Visual BASIC Features
It has a complete edifying and debugging facilities and has the ability to generate a Dynamic Link Libraries (DLL`S), it allows for easier management of document and it is easy to learn.
Visual Basic is a complete form of package for building user interface
Visual basic is a fairly easy language to pick up. However, it is generally not used to make very large applications. VB was also created for MS Windows.
Sample VB Program
Private Sub Form_Load()
' Execute a simple message box
that says "Hello, World!"
MsgBox "Hello, World!"
End Sub
REMEMBER
Please do not be mistaken by BASIC and Visual BASIC.
BASIC (PROGRAMMING LANGUAGE) IS AN EARLIER VERSION OF VISUAL BASIC.
Visual BASIC is MODIFIED for personal computer users, so we can say that it is a GUI VERSION of BASIC.
Recommended