Shulou(Shulou.com)06/02 Report--

This article will explain in detail how to achieve grouping and citation in regular expressions. The content of the article is of high quality, so the editor shares it for you as a reference. I hope you will have some understanding of the relevant knowledge after reading this article.

Selection, grouping, and reference character tables for regular expressions

Character meaning | Select, matching the subexpression on the left or the subexpression on the right of the symbol. A combination that combines several items into a unit that can be decorated with symbols such as * +? |, and can remember strings that match the combination to provide waiting references. Only combine, combine items into a segment element, but do not remember that the characters that match the group\ n match with the nth group match for the first time. The group is a subexpression in parentheses (or it may be nested). The group index is the number of left parentheses from left to right. (?: formal grouping does not encode about how to implement grouping and references in regular expressions. I hope the above content can be of some help to you and learn more knowledge. If you think the article is good, you can share it for more people to see.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.