Visual Basic - Language Syntax

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Visual Basic - Language Syntax

• CIS 241 - Advanced Visual Basic

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Data Types

• Integer Types (int)
• Real Types (sng, dbl)
• String (str)
• Boolean (bln)
• Date/Time (dtm)
• Currency (cur)

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Variables
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Variables/Constants Declared and Assigned

• Dim count as Integer
• Public name as String
• Private total as Integer
• Assignment
• count 100
• name Bob
• Constants
• const strName as String Mary

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Operators

• Arithmetic
• Relational
• Logical
• String

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Control Structures - Selection

• If condition Then
• statements
• End if
• If condition Then
• statements
• Else
• statement s
• End if
• The ifs may be nested

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Control Structures - Selection

• Select Case expression
• case value1
• statements
• case value2
• statements
• ..
• case else
• statements
• End Select

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Control Structures - Repetition

• Do While Until condition Pre Test
• statements
• Loop
• Do Post Test
• statements
• Loop While Until condition
• For
• For variable init To final step step_size
• statements
• Next

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Functions/Subroutines

• Public Private Function Name(Args) as
  DataType
• Name return value
• End Function
• Public Private Sub Name(Args)
• ...
• End Sub

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Arguments to Routines

• By value
• By reference (default)
• Private Function Multiply(ByVal X as Integer, _
• ByVal Y as Integer) as Integer
• Private Sub InOut(ByVal X as Real, Y as Real)

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Visual Basic Functions

• Numeric
• String
• Determining Data Type
• Date/Time
• Format

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Arrays - Declaring an Array

• Dim Name(numofElem) as DataType
• Number of Elements
• 5
• 1 to 5
• Multidimensional use multiple sizes
• (1 to 3, 1 to 5)

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Arrays - Using Arrays

• Dim scores(1 to 20) as Integer
• Dim I as Integer
• For I 1 to 20
• scores(I) 0
• Next

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With

• May be used to access several parts of an object
• Syntax
• With objName
• ..
• End With
• With txtString
• .Text Hello
• .FontSize 12
• End With