2. Code for Visual Basic
There are many sources of code
within the Visual Basic
documentation set. This topic
helps you get started in locating
that code. Note that some of this
code is contained within topics
that provide further explanation
or instructions on how to perform
a task, whereas some is contained
in special topics devoted only to
displaying a code example.
3. Visual Basic applications usually
consist of the following:
1.Forms-an application may
consits of one or more
forms.
2.Form controls-forms are
created with controls.
3.Code-programming language
that will direct application
execution.
4. * Input and output-are terms used to
describe the method of receiving data and
sending data from the computer to the user.
*Form module-a module file
that holds one or more
forms.
*Standard module-a file that
holds code that is not related to
a form.
*String-a series of
characters that is treated
as a single entity.
10. Data types
The three broad categories of data
in Visual Basic.
1.numeric-for numbers used in
data
2.string-for alphanumeric data
3.special-for special data type
including items that check box
values
11. VISUAL Description
BASIC DATA and range
TYPES
Data type that
takes one of two
BOOLEAN of the following
values true or
false.
Numeric values
BYTE without
decimals from
0 to 255
12. Here's a simple Visual Basic form. It looks just like any other form that you use in Windows applications. The header area has a caption, the control menu, and the minimize/ma
Holds tdate and time values
from 0:00:00(midnight) on
DATE january 1, 0001 through 11:59:59
PM on december
31, 9999
That represents
Decimal numbers with 28
decimal places
Numeric values from -
Double 1.79769313486232E+308
To
1.79769313486232E+308.
13. NUMERIC VALUES
INTEGER WITH NO DECIMAL
POINT FROM -32,768
TO 32,767
THE INTEGER DATA VALUES
LONG FROM-2,147,483,647
SPECIAL DATA TYPE
OBJECT THT HOLDS CONTROLS
AND FORMS.
SINGLE NUMERIC VALUES FROM -
3.402823E+38 TO 3.402823E+38.
14. THE DIM STATEMENTS LOCATION
Dim that appears in an event
procedure and can only be
used within that event
procedure called a Local
variable.Dim in a module’s
general section that can
access all the variables
within that module is called
Global variable.
15. The Dim statement is usually
written in the following format:
*Dim VarName As DataType
*VarName is a variable name
that you create .
16. Prefix Data type example
Bln Boolean blnlsOverTime
Byt Byte bytAge
Cur Currency curHourlyPay
Dtm Date dteFirstBegan
Dbl Double dblMicroMeasurement
17. Int Integer ingCount
Lng Long lngStarDistance
Obj Object objSoundClip
Sng Single sngYearSales
Str String strLastName
Vnt or
var Variant vntControlValue
18. Take note of the following code:
curNetSales =curGrissSales
- curCostOfSales
intResult = (1 + 2 ) * 3
19. Working with scientific
notation
Scientific notation is used
to represent extremely
large and small decimal
numbers without
including a lot of zeros or
other digits.
20. To convert a scientific
notation value to its real
value:
1.After the D or E ,raise 10 to the number.for
example,the +6 in the number 1.2345E+6 raise 10
to the 6th power to get 1,000,000.
2.Multiply the number at the left of
the D or E by the value in step
1.Multiply 1.2345 by the 1,000,000 to
get a result of 1,234,500.
21. Variables that hold data
To hold data that can change based on
calculations or the changes can be stated
within the application,variables must be
declared.
The Dim statement lets you recognize that the
variables holds the Currency data type and
The curToTalSales is the variable’s name.
22. Expressions and math
operators
Math operators allow
calculation and assignment
of expression results to
variables when you code
assignment statements that
contain expressions.
23. Visual basic primary
math operators
Operator Description
+ Adds two values
Subtracts one
- value from
another value
24. * Multiplies
two values
/ Divides one value
by another value
Raises a value
^ to a power
Concatenates
& (or +) two strings
