PHP regular expression example

The concept of regular expressions can be found in many places, so I won’t go into details here.
1. Is it related to text and characters?
The Chinese character range of Unicode is u4e00-u9fa5, the character corresponding to 4e00 is "一", and the Chinese character corresponding to 9fa5 is "龥", so the regular expression is like this:
1.1 matches all Chinese characters:

'/[一-龥]/u' or '/[/x{4e00}-/x{9fa5}]/u'

2. Is it related to the network and address?

2.1 Matching web page address:

"/https?:////([一-龥a-zA-Z///d/-]{1,30}/.){1,}([一-饥a-zA-Z]{2,9})(:/d{1,5})?([//|//]{1}[/w/./?=%]+) */u"

2.2 Matching email address:

'/[[:alnum:]._-]+@[[:alnum:]-]+/.([[:alnum:]-]+/. )*[[:alnum:]]+/'

3. Time and date related

3.1 Matching date

This is awesome, even leap years are included -_____-~ But I have not tested this.

"/(([0-9]{3}[1-9]|[0-9]{2}[1-9][0-9]{1}|[0-9]{1} [1-9][0-9]{2}|[1-9][0-9]{3})-(((0[13578]|1[02])-(0[1-9] |[12][0-9]|3[01]))|((0[469]|11)-(0[1-9]|[12][0-9]|30))|(02 -(0[1-9]|[1][0-9]|2[0-8]))))|((([0-9]{2})(0[48]|[2468] [048]|[13579][26])|((0[48]|[2468][048]|[3579][26])00))-02-29)/"