Boundary matchers and groups

The above points have taken up a lot of space. Now we will introduce some concepts of boundary matching characters and groups.

The general boundary matching characters are as follows:

Syntax	Description
^	Matches the beginning of the string (matches the beginning of each line in the case of multiple lines)
$	Matches the end of the string (matches the end of each line in the case of multiple lines)
\A	Matches only The beginning of the string
\Z	matches only the end of the string
\b	matches \w and \W
\B	[^\b]

grouping, expression enclosed in parentheses The formula is grouping. The grouping expression (...) actually treats this part of characters as a whole. Of course, there can be multiple groups. Every time a group is encountered, the number will be increased by 1, and quantifiers can also be added after the grouping.

There should be examples here, but considering the space issue, I won’t post them

Continuing Learning

new file

submit Reset Code

Automatic operation

Boundary matchers and groups

ElementaryImperial CMS enterprise imitation website tutorial

ElementaryNewbies with zero foundation in WordPress build personal blogs and corporate websites

ElementaryUltimate CMS zero-based website building instruction video

ElementaryFront-end project-Shangyou [HTML/CSS/JS technology comprehensive practice]

IntermediateVue3.0 from 0 to build a universal backend management system project practice

ElementaryZero-based front-end course [Vue advanced learning and practical application]

ElementaryWEB front-end tutorial [HTML5+CSS3+JS]

ElementaryQuick introduction to apipost

IntermediateVue3+TypeScript practical tutorial-enterprise-level project practice

ElementaryLet's briefly talk about starting a business in PHP

IntermediateVUE e-commerce project (front-end & back-end dual project actual combat)

ElementaryApipost practical application [api, interface, automated testing, mock]