Wiley Wrox's Visual Basic 2005 Express Edition Starter Kit 978-0-7645-9573-8 Manual Do Utilizador
Códigos do produto
978-0-7645-9573-8
However, to be fair, this section provides a quick rundown of where Visual Basic Express came from, just
so you know how far it has come. You’ll learn that Visual Basic has a rich past that has helped it evolve
into a solid, respected language that often leaves the more recent programming languages scrambling
for a foundation on which they can be compared against it.
so you know how far it has come. You’ll learn that Visual Basic has a rich past that has helped it evolve
into a solid, respected language that often leaves the more recent programming languages scrambling
for a foundation on which they can be compared against it.
The Basic programming language was first created back in 1964 — more than 40 years ago. Its very
inception was meant to make programming easy and more accessible. In fact, the name was actually
originally an acronym that stood for Beginner’s All-Purpose Symbolic Instruction Code. It was designed
as an interim step for students when they were learning programming concepts for more complex lan-
guages such as Fortran.
inception was meant to make programming easy and more accessible. In fact, the name was actually
originally an acronym that stood for Beginner’s All-Purpose Symbolic Instruction Code. It was designed
as an interim step for students when they were learning programming concepts for more complex lan-
guages such as Fortran.
In the 1970s, Bill Gates and Paul Allen got involved and worked with the company MITS (Micro
Instrumentation Telemetry Systems) to develop a version of Basic for the Altair PC. From that humble
beginning, Gates and company ported Basic to various other computing platforms, and by the end of
that decade, most computers had some form of the Basic language. It was from this starting point that
both its ease of use and popularity, as well as the disparaging opinions of many hardcore programmers,
sprang.
Instrumentation Telemetry Systems) to develop a version of Basic for the Altair PC. From that humble
beginning, Gates and company ported Basic to various other computing platforms, and by the end of
that decade, most computers had some form of the Basic language. It was from this starting point that
both its ease of use and popularity, as well as the disparaging opinions of many hardcore programmers,
sprang.
When DOS was first released for the early PCs, versions of a Basic interpreter were distributed along
with the operating system. Programming code can be executed in two ways — interpreted or compiled:
with the operating system. Programming code can be executed in two ways — interpreted or compiled:
❑
When it is compiled, it is assembled into the underlying machine code and can execute fast.
However, the compilation can take a while, and the program will not execute at all if even one
error is present.
However, the compilation can take a while, and the program will not execute at all if even one
error is present.
❑
An interpreter, on the other hand, requires another program to run through the code one line at
a time and execute it piece by piece. While this is slower than compiled code, it doesn’t require a
compilation routine before running, and it can execute working code up to the point where an
error occurs. Basic, and Visual Basic in particular, requires some form of a runtime component
because of the interpretive nature of the language compilers.
a time and execute it piece by piece. While this is slower than compiled code, it doesn’t require a
compilation routine before running, and it can execute working code up to the point where an
error occurs. Basic, and Visual Basic in particular, requires some form of a runtime component
because of the interpretive nature of the language compilers.
Microsoft took the command-line interpreter to the next step and introduced QuickBasic. QuickBasic did
actually compile the code into an executable, but it was still slow in comparison to the professional lan-
guages on the market. In the late 1980s and early 1990s, Alan Cooper created a prototype that enabled
a developer to dynamically add components, then called widgets, to a program running off a small,
custom-built language engine. Microsoft bought the concept and combined it with QuickBasic to form
Visual Basic 1.
actually compile the code into an executable, but it was still slow in comparison to the professional lan-
guages on the market. In the late 1980s and early 1990s, Alan Cooper created a prototype that enabled
a developer to dynamically add components, then called widgets, to a program running off a small,
custom-built language engine. Microsoft bought the concept and combined it with QuickBasic to form
Visual Basic 1.
And Then Came Visual Basic
Visual Basic was a revolution to Basic programmers worldwide as it enabled them to drag and drop con-
trols from a toolbox onto their forms without having to write any code at all. It also changed the focus of
the actual code to an event-oriented model that reacted to things happening, as opposed to making
things happen.
trols from a toolbox onto their forms without having to write any code at all. It also changed the focus of
the actual code to an event-oriented model that reacted to things happening, as opposed to making
things happen.
Visual Basic’s versatility enabled third-party companies to develop add-ins and additional controls that
Visual Basic programmers could use in their own applications, and the popularity of the language grew
hugely.
Visual Basic programmers could use in their own applications, and the popularity of the language grew
hugely.
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Chapter 1
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