VBA/Excel/Access/Word/Language Basics/Resume

Check the error number with Select Case statement

 
Sub SelectionSqrt()
    Dim cell As range
    Dim ErrMsg As String
    If TypeName(Selection) <> "Range" Then Exit Sub
    On Error GoTo ErrorHandler
    For Each cell In Selection
        cell.value = Sqr(cell.value)
    Next cell
    Exit Sub
ErrorHandler:
    Select Case Err
        Case 5 "Negative number
            Resume Next
        Case 13 "Type mismatch
            Resume Next
        Case 1004 "Locked cell, protected sheet
            MsgBox "The cell is locked. Try again."
            Exit Sub
        Case Else
            ErrMsg = Error(Err.number)
            MsgBox "ERROR: " & ErrMsg
            Exit Sub
    End Select
End Sub

Uses a Resume statement after an error occurs:

 
Sub EnterSquareRoot6()
    Dim Num As Variant
    Dim Msg As String
    Dim Ans As Integer
TryAgain:
    On Error GoTo BadEntry
    Num = InputBox("Enter a value")
    If Num = "" Then Exit Sub
    ActiveCell.value = Sqr(Num)
    Exit Sub
BadEntry:
    Msg = "An error occurred. Try again?"
    Ans = MsgBox(Msg, vbYesNo)
    If Ans = vbYes Then Resume TryAgain
End Sub

using the On Error Resume Next statement

 
Sub SelectionSqrt()
    Dim cell As range
    If TypeName(Selection) <> "Range" Then Exit Sub
    On Error Resume Next
    For Each cell In Selection
        cell.value = Sqr(cell.value)
    Next cell
End Sub