Example Analysis of Ajax and PHP regular expression validation form and CAPTCHA
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Pattern match:
\: escape characters such as:\ b escaped b
^: regular expression start symbol
$: regular expression end symbol
*: match the preceding character 0 or n times
+: matches the preceding character once or n times
?: match the preceding character 0 or 1 times
Matches all single characters except newline characters
| |: or, for example, x | y matches x or y |
{n}: matches the first n characters
{nrecoery m}: match at least n and up to m preceding characters
[xyz]: matches any character in parentheses
[^ xyz]: matching is equivalent to [0-9] except for any character in square brackets
\ w: matching any number or letter or underscore is equivalent to [A-Za-z0-9 _]
\ d: matches any number between 0Murray 9
Pattern modifier:
I: ignore case
Examples of common regular expressions:
/ / the user name consists of 6-18 alphanumeric underscores and cannot start with a number.
Var r_name=/ ^ [a-z]\ w {5pm 17} $/ I
/ / the password length cannot be less than six digits.
Var r_pwd=/ ^\ w {6,} $/
/ / all general email addresses
Var r_eamil=/ ^\ walled @\ w+ (\.)\ wrought /
/ / match an address of QQ Mail
/ / 861745122@qq.com
Var r_qq_email=/ ^\ d {5,} @ qq (\.) com$/
/ / match an email address of 163
Var r_163_email=/ ^\ way.163 (\.) com$/
/ / match a suffix name that may be .com | .net | .cn | .edu
Var email=/ ^\ walled @\ w+ (\.) com | net | cn | edu$/
/ / A valid age group is required
Var r_age=/ ^\ d {1pc2} $/
/ / if (age > = 18&&age "= 100)
/ / verify the mobile phone number: 11 digits at the beginning of 13 15 18
Var r_tel=/ ^ 1 [3pr 5pr 8]\ d {9} $/
/ / verify the ID number of 18 digits or 17 digits plus an X
Var r_s=/ ^\ d {18} |\ d {17} xgarbage I
/ / verify Chinese var reg=/ ^ [\ u4e00 -\ u9fa5] {2pr 17} $/
/ / php
$reg = "/ ^ [\ x {4e00} -\ x {9fa5}] $/ u"
The following is an example: account basic information login account: gender: male and female account security settings login password: real name: email address:
