visual basic 6 (vb6) data types

7/30/2019 Visual Basic 6 (VB6) Data Types

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Visual Basic 6 (VB6) Data Types,Modules and Operators


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Visual Basic uses buildingblocks such as Variables,

Data Types, Procedures,Functions and Control

Structures in its programmingenvironment.


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Modules

Code in Visual Basic is stored in theform of modules. The three kind ofmodules are Form Modules,Standard Modules and ClassModules.

A simple application may contain a

single Form, and the code residesin that Form module itself. As theapplication grows, additional Forms

are added and there may be a


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Modules To avoid the duplication of code, a

separate module containing a procedureis created that implements the common

code. This is a standard Module. Class module (.CLS filename extension)

are the foundation of the object orientedprogramming in Visual Basic.

New objects can be created by writingcode in class modules.


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Each module can contain:

Declarations : May includeconstant, type, variable and

DLL procedure declarations.Procedures : A sub function,

or property procedure thatcontain pieces of code thatcan be executed as a unit.


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These are the rules to follow when naming elements inVB - variables, constants, controls, procedures, and so

on:

A name must begin with a letter.

May be as much as 255 characters long(but don't forget that somebody has to

type the stuff!). Must not contain a space or an

embedded period or type-declaration

characters used to specify a data type;these are ! # % $ & @

Must not be a reserved word (that is part

of the code, like Option, for example)


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The dash, although legal, should beavoided because it may beconfused with the minus sign.Instead of First-name useFirst_name or FirstName.


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Data types in Visual Basic 6

By default Visual Basic variables are ofvariant data types. The variant data typecan store numeric, date/time or string

data. When a variable is declared, a data type

is supplied for it that determines the kindof data they can store.

The fundamental data types in VisualBasic including variant are integer, long,single, double, string, currency, byte and

boolean.


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Numeric

Byte

Store integer values in the range of 0 -255

IntegerStore integer values in the range of (-

32,768) - (+ 32,767)

Long

Store integer values in the range of (-

2,147,483,468) - (+ 2,147,483,468)

SingleStore floating point value in the range of

(-3.4x10-38) - (+ 3.4x1038)

DoubleStore large floating value which

exceeding the single data type value

Currencystore monetary values. It supports 4 digits

to the right of decimal point and 15digits to the left


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String

Use to store alphanumeric values. Avariable length string can store

approximately 4 billion charactersEx. Dim MyString As String * 10

MyString = "Chilkat" ' MyStringcontains "Chilkat " PrintRTrim$(MyString) ' prints "Chilkat"


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Date

Use to store date and time values. Avariable declared as date type can storeboth date and time values and it can

store date values 01/01/0100 up to12/31/9999

Ex. Use the Date data type to contain

date values, time values, or date andtime values.

The default value ofDate is 0:00:00

(midnight) on January 1, 0001.


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Boolean Boolean data types hold either a true or false value.

These are not stored as numeric values and cannotbe used as such. Values are internally stored as -1(True) and 0 (False) and any non-zero value is

considered as true. Dim runningVB As Boolean ' Check to see if program

is running on Visual Basic engine. If scriptEngine ="VB" Then runningVB = True End If


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Variant

Stores any type of data and isthe default Visual Basic data

type. In Visual Basic if wedeclare a variable without anydata type by default the data

type is assigned as default.Ex. Dim A Dim A as Variant


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Operators in Visual Basic

Operators Description Example Result

+ Add 5+5 10

- Substract 10-5 5

/ Divide 25/5 5

\ Integer Division 20\3 6

* Multiply 5*4 20

^Exponent (power

of)3^3 27

Mod

Remainder of

division 20 Mod 6 2

&String

concatenation"George"&"

"&"Bush""George Bush"


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Relational Operators

Operators Description Example Result

> Greater than 10>8 True

< Less than 10=Greater than or

equal to20>=10 True


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Logical Operators

OperatorsDescription

OROperation will be true if either of the

operands is true

ANDOperation will be true only if both the

operands are true

visual basic 6 (vb6) data types

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