java正则表达式从较大的字符串中排除特定的字符串
一段时间以来，我一直在努力反对这一点： 我想捕获所有 [az]+[0-9]? 字符序列，不包括 sin|cos|tan 等字符串。 因此，完成我的正则表达式作业后，以下正则表达式应该可以工作：
(?:(?!(sin|cos|tan)))\b[a-z]+[0-9]?
如您所见，我使用负向前查找和交替 - 非捕获组右括号后面的 \b 对于避免匹配 in of sin 等。正则表达式是有意义的，事实上，我已经尝试使用 RegexBuddy 和 Java 作为目标实现并获得想要的结果，但它不起作用使用 Java Matcher 和 Pattern 对象！ 有什么想法吗？
干杯
I have been banging my head against this for some time now:
I want to capture all [a-z]+[0-9]? character sequences excluding strings such as sin|cos|tan etc.
So having done my regex homework the following regex should work:
(?:(?!(sin|cos|tan)))\b[a-z]+[0-9]?
As you see I am using negative lookahead along with alternation - the \b after the non-capturing group closing parenthesis is critical to avoid matching the in of sin etc. The regex makes sense and as a matter of fact I have tried it with RegexBuddy and Java as the target implementation and get the wanted result but it doesn't work using Java Matcher and Pattern objects!
Any thoughts?
cheers
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\b位于错误的位置。它将寻找一个之前没有 sin/cos/tan 的字边界。但是，任何一个之后的边界都会在末尾有一个字母，因此它必须是词尾边界，如果下一个字符是 az，则不能是词尾边界。另外，负向预测（如果有效）会排除像
cost这样的字符串，如果您只是过滤掉关键字，我不确定您是否想要这样的字符串。我建议：
或者，更简单地说，您可以只匹配
\b[az]+[0-9]?\b，然后过滤掉关键字列表中的字符串。您并不总是需要在正则表达式中完成所有操作。The
\bis in the wrong place. It would be looking for a word boundary that didn't have sin/cos/tan before it. But a boundary just after any of those would have a letter at the end, so it would have to be an end-of-word boundary, which is can't be if the next character is a-z.Also, the negative lookahead would (if it worked) exclude strings like
cost, which I'm not sure you want if you're just filtering out keywords.I suggest:
Or, more simply, you could just match
\b[a-z]+[0-9]?\band filter out the strings in the keyword list afterwards. You don't always have to do everything in regex.所以你想要
[az]+[0-9]?（至少一个字母的序列，可选地后跟一个数字），除非该字母序列类似于以下之一sincostan？结果：
So you want
[a-z]+[0-9]?(a sequence of at least one letter, optionally followed by a digit), unless that letter sequence resembles one ofsincostan?results:
我忘记转义 java 的
\b，所以\b应该是\\b并且现在可以工作了。干杯
i forgot to escape the
\bfor java so\bshould be\\band it now works.cheers