Detailed description of the Regular Expression Form Verification instance code, regular expression instance

Detailed description of the Regular Expression Form Verification instance code, regular expression instance
Detailed description of the Regular Expression Form Verification instance code

This article describes detailed information about Regular Expression Form Verification instances. The content of Regular Expression Form Verification is as follows:

First, I want to explain some symbolic meanings to you.

* Matches the previous subexpression zero or multiple times;
^ Match the start position of the input string; $ match the end position of the input string
1./^ $/This is a common format.
2. Enter the functions to be implemented.
\ D matches a numeric character, which is equivalent to [0-9]
+ Match the previous subexpression once or multiple times;
? Match the previous subexpression zero or one time;

The following code analyzes the Regular Expression and verifies the regular expression. The specific code is as follows:

<! DOCTYPE html> 
The above content is the regular expression instance code for form verification, which is helpful to everyone.