[英]RegEx to match nested parentheses including the start and end parentheses
string st = "this (a,b) and this (s,(r,t),u) is a test";
var regex = new Regex(@"\(([^()]+| (?<Level>\()| (?<-Level>\)))+(?(Level)(?!))\)", RegexOptions.IgnorePatternWhitespace);
foreach (Match c in regex.Matches(input))
{
Console.WriteLine(c.Value.Trim('(', ')'));
}
The above C# code in .NET 4.5 correctly returns: NET 4.5中的上述C#代码正确返回:
a,b
s,(r,t),u
But I need the output including the parentheses as: 但是我需要包含括号的输出为:
(a,b)
(s,(r,t),u)
You can't do this with regex. 您不能使用正则表达式执行此操作。
You can use regex in a greedy or lazy way, but you can't apply logic to handle balancing of parentheses. 您可以以贪婪或懒惰的方式使用正则表达式,但不能应用逻辑来处理括号的平衡。
If you use \\(.*\\)
you will capture everything (greedy) from the first to the last parentheses and if you use \\(.*?\\)
(lazy or ungreedy) you will match from the first to the second one. 如果使用
\\(.*\\)
,则将捕获从第一个到最后一个括号的所有内容(贪婪);如果您使用\\(.*?\\)
(惰性或不贪婪的),则将匹配第一个到第二个。 Regex is no the right tool to match embedded strings (that's why they are also a bad idea to match embedded xhtml tags). 正则表达式不是匹配嵌入式字符串的正确工具(这就是为什么匹配嵌入式xhtml标记也不是一个好主意的原因)。
Imho, you should use a simple balance algorithm in a for loop. 恕我直言,您应该在for循环中使用简单的余额算法。 However, if you still want to use regex you can check this thread .
但是,如果您仍然想使用正则表达式,则可以检查此线程 。
If I understand correctly you currently have the output of: 如果我理解正确,那么您当前的输出为:
a,b
s,(r,t),u
Since you are using Trim('(', ')')
it removes the outer parentheses — to include them use: 由于您正在使用
Trim('(', ')')
因此会删除外部括号-要使用它们,请使用以下括号:
Console.WriteLine(c.Value)
Result: 结果:
(a,b)
(s,(r,t),u)
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