Excel VBA標準ライブラリ：基本的な機能と実用例

Sub StringOperations()
    Dim text As String
    text = "Hello, Excel VBA!"

    ' 文字列の長さを取得
    Dim length As Integer
    length = Len(text)
    MsgBox "Text length: " & length

    ' 部分文字列の取得
    Dim subText As String
    subText = Mid(text, 8, 5)
    MsgBox "Substring: " & subText

    ' 文字列の検索
    Dim position As Integer
    position = InStr(text, "Excel")
    MsgBox "'Excel' found at position: " & position

    ' 文字列の置換
    Dim replacedText As String
    replacedText = Replace(text, "Excel", "VBA")
    MsgBox "Replaced text: " & replacedText
End Sub

Sub NumericOperations()
    Dim number As Double
    number = -123.456

    ' 絶対値を取得
    Dim absValue As Double
    absValue = Abs(number)
    MsgBox "Absolute value: " & absValue

    ' 符号を取得
    Dim sign As Integer
    sign = Sgn(number)
    MsgBox "Sign: " & sign

    ' 整数部分を取得
    Dim intValue As Integer
    intValue = Int(number)
    MsgBox "Integer part: " & intValue

    ' 四捨五入
    Dim roundedValue As Double
    roundedValue = Round(number, 1)
    MsgBox "Rounded value: " & roundedValue

    ' 平方根を取得
    Dim sqrtValue As Double
    sqrtValue = Sqrt(144)
    MsgBox "Square root: " & sqrtValue
End Sub

Sub DateOperations()
    ' 現在の日付と時刻を取得
    Dim currentDate As Date
    Dim currentTime As Date
    currentDate = Date
    currentTime = Time
    MsgBox "Current date: " & currentDate
    MsgBox "Current time: " & currentTime

    ' 日付の加算
    Dim futureDate As Date
    futureDate = DateAdd("d", 10, currentDate)
    MsgBox "Future date (10 days later): " & futureDate

    ' 日付の差
    Dim dateDifference As Long
    dateDifference = DateDiff("d", currentDate, futureDate)
    MsgBox "Difference in days: " & dateDifference

    ' 年、月、日の取得
    Dim year As Integer
    Dim month As Integer
    Dim day As Integer
    year = Year(currentDate)
    month = Month(currentDate)
    day = Day(currentDate)
    MsgBox "Year: " & year & ", Month: " & month & ", Day: " & day

    ' 時、分、秒の取得
    Dim hour As Integer
    Dim minute As Integer
    Dim second As Integer
    hour = Hour(currentTime)
    minute = Minute(currentTime)
    second = Second(currentTime)
    MsgBox "Hour: " & hour & ", Minute: " & minute & ", Second: " & second
End Sub

Sub OtherFunctions()
    ' メッセージボックスの表示
    MsgBox "This is a message box.", vbInformation, "Message Box"

    ' 入力ボックスの表示
    Dim userInput As String
    userInput = InputBox("Please enter your name:", "Input Box")
    MsgBox "Hello, " & userInput & "!", vbInformation, "Greeting"

    ' 変数が空であるかの確認
    Dim emptyVar As Variant
    If IsEmpty(emptyVar) Then
        MsgBox "The variable is empty.", vbInformation, "IsEmpty"
    End If

    ' 変数が数値であるかの確認
    Dim numericVar As Variant
    numericVar = 123
    If IsNumeric(numericVar) Then
        MsgBox "The variable is numeric.", vbInformation, "IsNumeric"
    End If
End Sub