vba-excel meaning of <> (angled brackets or greater-than and less-than symbols)

I am working with find functions in VBA Excel, so when I ran into problems I pulled some example code from the help provided in Excel. I took their code that illustrates a basic find function and pasted it into a macro. On running the macro, I get a "Runtime error '91'" and the debugger highlights the line of code containing the angled brackets <>. These are the part of the code that I cannot understand.

Can anyone tell me what these brackets represent?

Sub exampleFindReplace()

With Worksheets(1).Range("a1:a500")
Set c = .Find(2, LookIn:=xlValues)
If Not c Is Nothing Then
    firstAddress = c.Address
    Do
        c.Value = 5
        Set c = .FindNext(c)
    Loop While Not c Is Nothing And c.Address <> firs开发者_StackOverflow中文版tAddress
End If
End With

End Sub

The <> operator means c.Address Is Not Equal To firstAddress.

In a C-style language this would be equivalent to c.Address != firstAddress.

Side note, I think you are getting error 91 (Object variable or With block variable not set.) because the line of code Loop While Not c Is Nothing And c.Address <> firstAddress will always try to execute the second condition (c.Address <> firstAddress) even if the first (While Not C Is Nothing) evaluates to false. Thus the call on c.Address will raise the exception.

Try writing the code like this as it will not allow that to happen:

Sub exampleFindReplace()

With Worksheets(1).Range("a1:a500")
Set c = .Find(2, LookIn:=xlValues)
If Not c Is Nothing Then
    firstAddress = c.Address
    Do
        c.Value = 5
        Set c = .FindNext(c)
        If c Is Nothing Then Exit Do
    Loop While c.Address <> firstAddress
End If
End With

End Sub