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 这是更短，100倍以上的可读性。 
 
 编辑 Wug编辑了MarkJ的原始答案中的代码，代码如下： 
 
If (item Is Nothing)
    Then Exit Sub ' we got a non-element
ElseIf (lastSelected Is Nothing) Then
    Set lastSelected = item ' we got our first go 
ElseIf (item = lastSelected) Then
    Exit Sub ' we already had what we got
End If
Set lastSelected = item ' we got something new 
 
 这里是MarkJ的回复。 一个嵌套，如果只有一个Set。 看起来很整洁。 
 
If (item Is Nothing) Then 
  Exit Sub ' we got a non-element 
ElseIf Not (lastSelected Is Nothing) Then ' not our first go
  If (item = lastSelected) Then 
    Exit Sub ' we already had what we got 
  End If 
End If
Set lastSelected = item ' we got something new
' does stuff here? @Wug is that true?
 
 
 
 要比较VB6中的引用相等性，使用项目是LastSelected。 因为item = lastSelected可能会评估对象中的默认属性，并对它们进行比较！ 
 
 
 由于简洁似乎是一个目标，请考虑这一点。 如果您在条件X为True时退出Sub，则不需要稍后再检查X. 这是假的！ 除非它在评估之间改变它的值（例如X是一个检查系统时钟的函数）。 您正在检查项目是否是lastSelected，然后是否不是。 如果项目没有什么是假的，不要麻烦检查项目是不是什么是真的！ 
 
 
 VB6不会与古代版本的Basic向后兼容 
 
 
 不要担心VB6不是其他语言，而放松！ 
 

This is shorter and 100x more readable. 
 
EDIT Wug edited the code in MarkJ's original answer, into this:
 
If (item Is Nothing)
    Then Exit Sub ' we got a non-element
ElseIf (lastSelected Is Nothing) Then
    Set lastSelected = item ' we got our first go 
ElseIf (item = lastSelected) Then
    Exit Sub ' we already had what we got
End If
Set lastSelected = item ' we got something new 
 
Here's MarkJ's edit in response. One nested if, but only one Set. Seems neater to me. 
 
If (item Is Nothing) Then 
  Exit Sub ' we got a non-element 
ElseIf Not (lastSelected Is Nothing) Then ' not our first go
  If (item = lastSelected) Then 
    Exit Sub ' we already had what we got 
  End If 
End If
Set lastSelected = item ' we got something new
' does stuff here? @Wug is that true?
 
 
 
To compare reference equality in VB6 use item Is LastSelected. Because item = lastSelected will probably evaluate the default properties in the objects and compare those instead! 
 
 
Since brevity appears to be a goal, consider this. If you Exit Sub when condition X is True, you don't need to check X again later. It is False! Unless it changes its value in between evaluations (e.g. X is a function that checks the system clock). You were checking whether item was lastSelected, then whether it wasn't. And if item Is Nothing is False, do not bother to check whether item Is Not Nothing is True! 
 
 
VB6 does not short circuit for backwards compatibility with ancient versions of Basic 
 
 
Stop worrying that VB6 is not some other language and relax!