Regular expression quick-check table

Regular expressions are always useful in programming, and in personal cognition, the following programming languages are used, of course:

(1) Web front end: JavaScript

(2) Web backend: ASP, JSP, PHP

(3) Mobile: Android, IOS

Some basic descriptions and usages of regular expressions are listed here, which makes it easy for individuals to find them at any time.

PS: Content from the network, non-personal original;

character	Description
\	Marks the next character as a special character, or a literal character, or a backward reference, or an octal escape. For example, " n " matches the character " n ". " \n " matches a line break. Serial "matches" "and" "matches" " \\ \ \( ( .
^	Matches the starting position of the input string. If the multiline property of the RegExp object is set, ^ also matches the \n position after "or" \r .
$	Matches the end position of the input string. If the multiline property of the RegExp object is set, $ also matches the \n position before "" or "" \r .
*	Matches the preceding subexpression 0 or more times. For example, zo* can match "" z and " zoo ". * Equivalent to {0,}.
+	Matches the preceding subexpression one or more times. For example, " zo+ can match" zo and " zoo , but cannot match" " z . + equivalent to {1,}.
?	Matches the preceding subexpression 0 or one time. For example, "" can Match "" or "" do(es)? does in "." does is do equivalent to {0,1}.
N	N is a non-negative integer. Matches the determined n times. For example, "" o{2} cannot Match "" Bob in " o , but can match food two o in" ".
{N,}	N is a non-negative integer. Match at least n times. For example, "" o{2,} cannot Match " Bob in" o , but can match foooood all o in "". "" is o{1,} equivalent to " o+ ". "" o{0,} is equivalent to " o* ".
{N,m}	Both M and n are non-negative integers, where n<=m. Matches at least n times and matches up to M times. For example, "" o{1,3} will match the fooooood top three o in "". "" is o{0,1} equivalent to " o? ". Note that there can be no spaces between a comma and two numbers.
?	When the character immediately follows any other restriction (*,+,?,{n},{n,},{n,m}), the matching pattern is non-greedy. The non-greedy pattern matches the searched string as little as possible, while the default greedy pattern matches as many of the searched strings as possible. For example, for the string " oooo ", "" o+? will match a single "" and "" o o+ will match all " o ".
.	Matches \ n any single character except "". To match \ n any character including "", use (.|\n) a pattern like "".
(pattern)	Match pattern and get this match. The obtained matches can be obtained from the resulting matches collection, the Submatches collection is used in VBScript, and the $0...$9 property is used in JScript. To match the parentheses character, use " \( or" \) .
(?:p Attern)	Matches pattern but does not get a matching result, which means that this is a non-fetch match and is not stored for later use. This is useful in using the or character " (|) " to combine the various parts of a pattern. For example, " industr(?:y|ies) " is a industry|industries more abbreviated expression than "".
(? =pattern)	Positive pre-check to match the find string at the beginning of any string matching pattern. This is a non-fetch match, which means that the match does not need to be acquired for later use. For example, " Windows(?=95|98|NT|2000) can match" Windows2000 in Windows , but not " Windows3.1 in" Windows . Pre-checking does not consume characters, that is, after a match occurs, the next matching search starts immediately after the last match, rather than starting with the character that contains the pre-check.
(?! Pattern	Forward negation, matching the lookup string at the beginning of any mismatched pattern string. This is a non-fetch match, which means that the match does not need to be acquired for later use. For example Windows(?!95|98|NT|2000) , "can match" Windows3.1 in Windows , but cannot match "" Windows2000 in Windows "". Pre-check does not consume characters, that is, after a match occurs, the next matching search starts immediately after the last match, rather than starting with the character that contains the pre-check
(? <=pattern)	Reverse affirmation pre-check, and positive forward certainly pre-check class quasi, just the opposite direction. For example, " (?<=95|98|NT|2000)Windows can match" 2000Windows in Windows , but not " 3.1Windows in" Windows .
(? <!pattern)	Reverse negation of pre-check, and positive negative pre-check class quasi-, just the opposite direction. For example (?<!95|98|NT|2000)Windows , "can match" 3.1Windows in Windows , but cannot match "" 2000Windows in Windows "".
X|y	Match x or Y. For example, " z|food can match" z or " food ." "" matches "" or "" (z|f)ood zood food .
[XYZ]	The character set is combined. Matches any one of the characters contained. For example, "" can Match "" in "" [abc] plain a .
[^XYZ]	Negative character set. Matches any character that is not contained. For example, "" can Match "" in "" [^abc] plain p .
[A-z]	The character range. Matches any character within the specified range. For example, " [a-z] " can match a z any lowercase alphabetic character in the "to" range.
[^a-z]	A negative character range. Matches any character that is not in the specified range. For example, " [^a-z] " can match any character that is not in the " a to" z range.
\b	Matches a word boundary, which is the position between a word and a space. For example, "" can Match "in" er\b never er , but not " verb in" er .
\b	Matches a non-word boundary. "" Can Match "in" er\B verb er , but not " never in" er .
\cx	Matches the control character indicated by X. For example, \cm matches a control-m or carriage return. The value of x must be one of a-Z or a-Z. Otherwise, c is considered to be a literal " c " character.
\d	Matches a numeric character. equivalent to [0-9].
\d	Matches a non-numeric character. equivalent to [^0-9].
\f	Matches a page break. Equivalent to \x0c and \CL.
\ n	Matches a line break. Equivalent to \x0a and \CJ.
\ r	Matches a carriage return character. Equivalent to \x0d and \cm.
\s	Matches any whitespace character, including spaces, tabs, page breaks, and so on. equivalent to [\f\n\r\t\v].
\s	Matches any non-whitespace character. equivalent to [^ \f\n\r\t\v].
\ t	Matches a tab character. Equivalent to \x09 and \ci.
\v	Matches a vertical tab. Equivalent to \x0b and \ck.
\w	Matches any word character that includes an underscore. Equivalent to " [A-Za-z0-9_] ".
\w	Matches any non-word character. Equivalent to " [^A-Za-z0-9_] ".
\xn	Match N, where n is the hexadecimal escape value. The hexadecimal escape value must be two digits long for a determination. For example, " \x41 match" A . "" \x041 is equivalent to " \x04&1 ". ASCII encoding can be used in regular expressions:
\num	Matches num, where num is a positive integer. A reference to the obtained match. For example, " (.)\1 " matches two consecutive identical characters.
\ n	Identifies an octal escape value or a backward reference. n is a backward reference if \ n is preceded by at least one of the sub-expressions obtained. Otherwise, if n is the octal number (0-7), N is an octal escape value.
\nm	Identifies an octal escape value or a backward reference. If at least NM has obtained a subexpression before \nm, then NM is a backward reference. If there are at least N fetches before \nm, then n is a backward reference followed by the literal m. If none of the preceding conditions are met, if both N and M are octal digits (0-7), then \nm will match the octal escape value nm.
\nml	If n is an octal number (0-3) and both M and L are octal digits (0-7), the octal escape value NML is matched.
\un	Match N, where N is a Unicode character represented by four hexadecimal digits. For example, \u00a9 matches the copyright symbol (©).

Common Regular Expressions

User name	/^[a-z0-9_-]{3,16}$/
Password	/^[a-z0-9_-]{6,18}$/
Hexadecimal value	/^#? ([a-f0-9]{6}| [A-f0-9] {3}) $/
E-Mail	/^ ([a-z0-9_\.-]+) @ ([\da-z\.-]+) \. ([A-z\.] {2,6}) $/ /^[a-z\d]+ (\.[ a-z\d]+) *@ ([\da-z] (-[\da-z])?) +(\. {A} [a-z]+] +$/
Url	/^ (https?:\ /\/)? ([\da-z\.-]+) \. ([A-z\.] {2,6}) ([\/\w \.-]*) *\/?$/
IP Address	/((2[0-4]\d|25[0-5]| [01]?\d\d?] \.) {3} (2[0-4]\d|25[0-5]| [01]?\d\d?] / /^(?:(? : 25[0-5]|2[0-4][0-9]| [01]? [0-9] [0-9]?) \.) {3} (?: 25[0-5]|2[0-4][0-9]| [01]? [0-9] [0-9]?) $/
HTML tags	/^< ([a-z]+) ([^<]+) * (?:> (. *) <\/\1>|\s+\/>) $/
Delete code \ \ Comment	(? <!http:|\s)//.*$
The range of Chinese characters in Unicode encoding	/^[\u2e80-\u9fff]+$/

Regular expression quick-check table