Visual Basic Reference

• Visual Basic isn't case-sensitive, but it preserves the capitalization in the statement where the name is declared.

http://msdn.microsoft.com/en-us/library/ee441152.aspx

TypesEdit

Variant

• Default data type if not specify
• Slower to process and large foot-print

Array

• Store elements of single type
• Index start from 0. Declaration also assume start from 0. Can be change with "Option Base" at the top of a module.
• Inefficient is don't know the exact size of the array
• Contiguous
• Declare: Dim myArray(4) As Currency 'declare 5 elements
• Access: myArray(index)
• Multi-dimension: Dim myArray(0 To 4, 0 To 9) As Integer 'declare 5x10 array. Max 60-dimensional
• Note: Array of variant data

Dim myArray(5) As Variant or

Dim myArray As Variant

myArray = Array(...)

Collection

• Like dynamic array, elements can be of different types
• Declare: Dim myArray As Collection
• Add: myArray.Add "Element1", "Element2"
• Access: myArray.Item(1) or myArray(1) or myArray("Element2")
• Remove: myArray.Remove 1 or myArray.Remove "Element2"
• Remove all: Set myArray = New Collection or Set myArray = Nothing

SpecialEdit

Empty

• Only for variant
• Initial value of variant type
• Check with IsEmpty()

Null

• For variant, fields, and controls
• Check with IsNull()
• Cannot be compared to each other

Conditional LogicEdit

If StatementEdit

If <condition> Then

ElseIf <condition> Then

Else

End If

For LoopEdit

Use "Exit For" to exit the loop

• For counter=<start> To <end> [Step <step>]
  Next [counter]

• For Each <object> In <collection|array>
  Next [counter]

Do LoopEdit

Use "Exit Do" to exit the loop

• Do While <condition>
  Loop

• Do
  Loop While <condition>

• Do Until <condition>
  Loop

• Do
  Loop Until <condition>

Select Case StatementEdit

Select Case <expression>

Case [value]

Case [multi values: 2, 5, 7]

Case [range: 2 To 7]

Case [comparison: val > 10]

Case Else

End Select

AssignmentEdit

• Use = to assign to a variable or constant
• Use of Let is optional
• Use Set to assign object

CommentEdit

• Start with apostrophe(') or Rem

Line ContinuationEdit

• Use underscore(_)

String ConcatenationEdit

• Use ampersand(&)

Function and SubroutineEdit

FunctionEdit

• Return value
• Set variable name the same as function name to return the value
• To ignore the return value, call the function the way we call Sub--without parenthesis and pass parameters as usual

SubroutineEdit

• Does not return any value
• Call: mySub arg1, arg2 or Call mySub(arg1,arg2)

Named ArgumentsEdit

Say we have Sub mySub(arg1 As Integer, arg2 As String)
We can call: mySub(5, "Friday") --parameter positions are important or
Use named parameters: mySub(arg2:="Friday", arg1:=5) --parameter positions are not important

Optional ArgumentsEdit

Sub mySub(arg1 As Integer, Optional arg2 As String) 'without default value
Sub mySub(arg1 As Integer, Optional arg2="Holiday" As String) 'with default value