Regular expression Form validation instance code detailed

Regular expression Form validation instance code detailed

This article mainly describes the regular expression form validation examples of relevant information, we can refer to the following. The regular expression form validation details are as follows:

First of all, to explain some symbolic relevance.

* Match the preceding sub-expression 0 or more times;
^ matches the starting position of the input string; $ matches the end position of the input string
1./^$/this is a generic format.
2. Enter the functions that need to be implemented.
\d matches a numeric character, equivalent to [0-9]
+ Match the preceding subexpression one or more times;
？ Matches the preceding subexpression 0 or one time;

Here is a piece of code to analyze the form validation regular expression, the specific code is as follows:

<! DOCTYPE html> 
The above content is the form validation regular expression instance code, hope to be helpful to everybody.
Regular expression Form validation instance code detailed