Excel VBAの変数宣言：効率的なデータ管理とメモリ使用の基礎

Dim 変数名 As データ型

Dim myNumber As Integer

Sub BasicVariableExample()
    ' 整数型の変数を宣言
    Dim myNumber As Integer
    
    ' 変数に値を代入
    myNumber = 10
    
    ' 変数の値を使用して計算
    myNumber = myNumber * 2
    
    ' 変数の値をメッセージボックスに表示
    MsgBox "The value of myNumber is " & myNumber
End Sub

Sub MultipleDataTypesExample()
    ' さまざまなデータ型の変数を宣言
    Dim myString As String
    Dim myNumber As Integer
    Dim myDouble As Double
    Dim myDate As Date
    
    ' 変数に値を代入
    myString = "Hello, VBA!"
    myNumber = 42
    myDouble = 3.14159
    myDate = #2023/12/31#
    
    ' 変数の値をメッセージボックスに表示
    MsgBox "String: " & myString & vbCrLf & _
           "Integer: " & myNumber & vbCrLf & _
           "Double: " & myDouble & vbCrLf & _
           "Date: " & myDate
End Sub

Sub LocalVariableExample()
    Dim myLocalVariable As Integer
    myLocalVariable = 100
    MsgBox "Local variable value: " & myLocalVariable
End Sub

' モジュールの先頭で宣言
Dim myModuleVariable As Integer

Sub ModuleVariableExample1()
    myModuleVariable = 200
    MsgBox "Module variable value in Example1: " & myModuleVariable
End Sub

Sub ModuleVariableExample2()
    MsgBox "Module variable value in Example2: " & myModuleVariable
End Sub

' モジュールの先頭で宣言
Public myGlobalVariable As Integer

Sub GlobalVariableExample1()
    myGlobalVariable = 300
    MsgBox "Global variable value in Example1: " & myGlobalVariable
End Sub

Sub GlobalVariableExample2()
    MsgBox "Global variable value in Example2: " & myGlobalVariable
End Sub