vba 是在等式比较中被视为零的空值
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vba are empty values treated as zeroes in equality comparison
提问by Siraj Samsudeen
I am trying to skip records which either have a zero as the value or is empty. As of now, i have the following code that checks for both explicitly, but I feel that the second check is redundant. But I want to confirm that I am right so that I can remove the second part of the IF
我试图跳过值为零或为空的记录。截至目前，我有以下代码明确检查两者，但我觉得第二次检查是多余的。但我想确认我是对的，以便我可以删除 IF 的第二部分
IF (CellInValue(RowInCrnt, ColInCrnt) = 0 Or CellInValue(RowInCrnt, ColInCrnt) = "") Then
回答by GSerg
No, ""is not equal to 0and will produce a type mismatch in a strongly typed scenario, or won't come out as equal if used as Variant.
不，""is not equal to0并且在强类型场景中会产生类型不匹配，或者如果用作Variant.
When the cell is empty, it's also not the same as zero, but it will come out as same, because in VB, Empty = 0gives Truebecause of implicit conversion happening in the background.
Same for Empty = "", will also give Truefor the same reason.
当单元格为空时，它也不与零相同，但它会以相同的方式出现，因为在 VB 中，由于在后台发生隐式转换而Empty = 0给出True。
同样为Empty = ""，也会True出于同样的原因给予。
So you need both checks.
所以你需要两个检查。
回答by Daniel
GSerg is completely correct.
GSerg 是完全正确的。
If you really wanted to avoid doing 2 different checks, you could change your If to something like this:
如果您真的想避免进行 2 次不同的检查，您可以将 If 更改为如下所示：
If Clng(0 & CellInValue(RowInCrnt, ColInCrnt)) = 0 then
This returns true when CellInValue(RowInCrnt, ColInCrnt)is "", Empty, or 0.
当CellInValue(RowInCrnt, ColInCrnt)为 ""、Empty 或 0时返回 true 。
Though if your function could return letters instead of numbers, this will have a type mismatch error in that case.
尽管如果您的函数可以返回字母而不是数字，则在这种情况下会出现类型不匹配错误。
