Option Compare statement
VBA里可以定义默认使用的compare方法：
' Set the string comparison method to Binary.
Option Compare Binary ' That is, "AAA" is less than "aaa".
' Set the string comparison method to Text.
Option Compare Text ' That is, "AAA" is equal to "aaa".
This example uses the Option Compare statement to set the default string comparison method. The Option Compare statement is used at the module level only.
If used, the Option Compare statement must appear in a module before any procedures.
If a module doesn't include an Option Compare statement, the default text comparison method is Binary.
- Option Compare Binary results in string comparisons based on a sort order derived from the internal binary representations of the characters. In Microsoft Windows, sort order is determined by the code page. A typical binary sort order is shown in the following example:
A < B < E < Z < a < b < e < z < À < Ê < Ø < à < ê < ø
- Option Compare Text results in string comparisons based on a case-insensitive text sort order determined by your system's locale. When the same characters are sorted by using Option Compare Text, the following text sort order is produced:
(A=a) < ( À=à) < (B=b) < (E=e) < (Ê=ê) < (Z=z) < (Ø=ø)
参考：
Option Compare statement (VBA) | Microsoft Learn
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