The above expression combines character groups, greedy operators, back-tracking, and atomic groups to match nested tags.
以上表达式综合运用了字符分组,贪婪操作符、回溯,以及最小化组团来匹配嵌套标签。
3
Grouping is indicated by parentheses: any sub-expression contained in parentheses is treated as if it were atomic for the purpose of further grouping or repetition.