You can use that wildcard at any location of the filter string to match any number of unknown characters.

您可以在过滤器字符串的任何位置使用该通配符，以匹配未知字符的数量。

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If you omit it, your regex would match any string that begins with a letter, contains two to nine alphanumeric characters, and any number of any other characters.

如果忽略掉它，regex将匹配开头为字母、包含2至9个字母数字字符以及任意数目的任何其他字符的所有字符串。

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First, it improves the efficiency of the lexical analysis during the parsing of the view state string since there is no longer any need to match characters or parse tokens.

第一个目的是改进解析ViewState字符串时进行词法分析的效率，因为此时不再需要匹配字符或解析标记。

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