正则表达式匹配条件字符串
例如，如果我有以下字符串：
99%89 (should match)
99%? (should match)
?%99 (should match)
?%? (should not match)
?%99%99 (should match)
99%99%99%? (should match)
本质上，第一个或第二个元素可以是 ? 或一个数字，但两个元素都不能是 ?。我试着想像这样的事情：
[0-9]*|[?](?!?)[%][0-9]*|[?]
但这不会产生正确的答案，任何帮助将不胜感激
回答
使用您显示的样本，您能否尝试以下操作。
^(?:(?:?(?:(?:%d+){1,})?)|(?:(?:(?:d+%){1,})??(?:(?:%d+){1,})?)|(?:d+%d+))$
上述正则表达式的在线演示
说明：为以上添加详细说明。
^(?: ##Matching from starting of the value, starting a non-capturing group from here.
(?:? ##Starting non-capturing group(one for understanding purposes) matching literal ? here.
(?:(?:%d+){1,})? ##In a non capturing group looking for % with 1 or more occurrences of digits and matching this group match keeping it optional.
)| ##Closing one non-capturing group here, with OR condition here.
(?: ##Starting non-capturing group(two) here.
(?:(?:d+%){1,})?? ##Looking for digits with % one or more occurrences in a non-capturing group keeping it optional followed by ?
(?:(?:%d+){1,})? ##Checking for % digits one or more occurrences in a non-capturing group keeping it optional followed by ?
)| ##Closing two non-capturing group here, with OR condition here.
(?:d+%d+) ##In a non-capturing group looking for 1 or more digits % one or more digits
)$ ##Closing 1st non-capturing group at the end of value.