Home > Article > Backend Development > Regular expression system tutorial (1)_PHP tutorial
1. Introduction
At present, regular expressions have been widely used in many software, including *nix (Linux, Unix, etc.), HP and other operating systems, PHP, C#, Java and other development environments, and many You can see the shadow of regular expressions in all application software.
The use of regular expressions can achieve powerful functions in a simple way. In order to be simple and effective yet powerful, the regular expression code is more difficult and not easy to learn, so it requires some effort. After getting started, it is relatively simple and effective to use it by referring to certain references.
Example: ^.+@.+..+$
Such code has scared me away many times. Maybe many people are scared away by such code. Continuing reading this article will give you the freedom to apply code like this too.
Note: Part 7 here seems to be somewhat repetitive with the previous content. The purpose is to re-describe the parts in the previous table to make these contents easier to understand.