Regular expression character meaning

Characters
Meaning: For a character, it is usually expressed as literal meaning that the next character is a special character and is not interpreted.
For example:/b/matches the character ' B ', by adding a backslash in front of B, which is/b/, the character becomes a special character, indicating
Match the dividing line of a word.
Or:
For several characters, the usual description is special, which indicates that the characters immediately followed are not special, but should be interpreted literally.
For example: * is a special character that matches any character (including 0 characters); For example:/a*/means match 0 or more a. In order to match the literal *, a backslash is added to the front of a, for example:/a*/matches ' A * '.
Character ^
Meaning: The character that represents the match must be at the front.
For example:/^a/does not match "an A," in the ' a ', but matches "an A." The "A" in the front.
Character $
Meaning: Similar to ^, matches the last character.
For example:/t$/does not match ' t ' in ' eater ', but matches ' t ' in ' eat '.
Characters
Meaning: matches the preceding character 0 or n times.
For example:/bo*/matches ' B ' in ' boooo ' or ' a bird warbled ' in ' a ghost booooed ', but does not match ' agoat G '
Any characters in the runted ".
Character +
Meaning: Matches the character preceding the + sign 1 or n times. Equivalent to {1,}.
For example:/a+/matches ' a ' and ' Caaaaaaandy ' in ' Candy '. All ' a ' in the.
Character?
Meaning: match the preceding character 0 or 1 times.
For example:/e?le?/matches ' el ' and ' angle ' in ' Angel '. In the ' Le '.
Character.
Meaning: (decimal point) matches all the individual characters except the line break.
For example:/.n/matches "Nay, an apple was on the tree" in the ' an ' and ' on ', but does not match ' nay '.
Character (x)
Meaning: Match ' x ' and record the matching value.
For example:/(foo)/Match and record "Foo bar." The ' foo ' in the matching substring can be found in the result array of the vegetarian [1], ..., [n] Return
Back, or the property of the RegExp object, ..., returns.
Character X│y
Meaning: Match ' x ' or ' Y '.
For example:/green│red/matches ' green ' and ' Red apple ' in ' green apple '. In the ' Red '.
Character {n}
Meaning: n Here is a positive integer. Matches the preceding n characters.
For example:/a{2}/does not match ' a ' in ' Candy, ' but matches all ' a ' and ' Caaandy ' in ' Caandy, '. In front of the two ' a '.
Character {n,}
Meaning: n Here is a positive integer. Matches at least n preceding characters.
For example:/a{2,} does not match ' a ' in ' Candy ', but matches all ' a ' and ' Caaaaaaandy ' in ' Caandy '. All ' a ' in the
Character {n,m}
Meaning: Both N and m here are positive integers. Matches at least n characters up to M preceding.
For example:/a{1,3}/does not match any characters in "Cndy", but matches "candy," in the first two of ' a ', ' Caandy, '
' A ' and ' Caaaaaaandy ' in front of the three ' a ', note: even if "Caaaaaaandy" has a lot of ' a ', but only match the previous three ' a ' is "AAA".
character [XYZ]
Meaning: A list of characters that matches any of the characters in the list. You can use hyphens-to indicate a range of characters.
For example: [ABCD] is the same as [a-c]. They match ' C ' in ' B ' and ' ache ' in ' brisket '.
character [^XYZ]
Meaning: A character complement, that is, it matches everything except the listed characters. You can use hyphens-to indicate a range of characters.
For example: [^ABC] and [^a-c] are equivalent, they first match ' R ' and ' chop ' in ' brisket '. In the ' H '.
Character
Meaning: Match a space (do not confuse with B)
Character B
Meaning: Match the dividing line of a word, such as a space (do not confuse)
For example:/bnw/matches ' no ' in ' Noonday ',/wyb/matches ' possibly yesterday. ' In the ' ly '.
Character B
Meaning: Match the non-dividing line of a word
For example:/wbn/matches ' on ' in "Noonday",/ybw/matches "possibly yesterday." In the ' ye '.
Character CX
Meaning: The x here is a control character. Matches the control character of a string.
For example:/cm/matches a control-m in a string.
Character D
Meaning: Match a number, equivalent to [0-9].
For example:/d/or/[0-9]/matches "B2 is the suite number." In the ' 2 '.
Character D
Meaning: matches any non-number, equivalent to [^0-9].
For example:/d/or/[^0-9]/matches "B2 is the suite number." In the ' B '.
Character F
Meaning: Match a single form character
Character N
Meaning: Match a line break
Character R
Meaning: Match a carriage return character
Character S
Meaning: Match a single white space character, including spaces, tab,form feeds, line breaks, equivalent to [FNRTV].
For example:/sw*/matches "foo bar." In the ' bar '.
Character S
Meaning: matches a single character except white space, equivalent to [^ FNRTV].
For example:/s/w* matches "foo bar." In the ' foo '.
Character T
Meaning: Match a tab
Character V
Meaning: Match a head tab
Character W
Meaning: Matches all numbers and letters as well as underscores, equivalent to [a-za-z0-9_].
For example:/w/matches "Apple," in the ' a ', ". 28," In the ' 5 ' and ' 3D. ' In the ' 3 '.
Character W
Meaning: Matches other characters except numbers, letters, and underscores, equivalent to [^a-za-z0-9_].
For example:/w/or/[^ $A-za-z0-9_]/match "50%." In the '% '.
Character N
Meaning: n Here is a positive integer. The value of the N of the last substring of a regular expression (counting the left parenthesis).
For example:/apple (,) sorange1/matches "Apple, orange, cherry, peach." In the ' Apple, Orange ', here's a more complete example.
Note: If the number in the left parenthesis is smaller than the number specified by N, then N takes a line of octal escape as a description.
Characters Ooctal and Xhex
Meaning: The ooctal here is an octal escape value, while Xhex is a hexadecimal escape value that allows the embedding of ASCII code in a regular expression
Attached: The following table is a complete list of metacharacters and its behavior in the context of regular expressions:
Character description
\
Marks the next character as a special character, or a literal character, or a back reference, or an octal escape character. For example, ' n ' matches the character "n". ' \ n ' matches a newline character. The sequence ' \ ' matches "and" \ ("Matches" (".
^
Matches the starting position of the input string. If the Multiline property of the RegExp object is set, ^ also matches the position after ' \ n ' or ' \ R '.
$
Matches the end position of the input string. If the Multiline property of the RegExp object is set, $ also matches the position before ' \ n ' 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 not "Z". + equivalent to {1,}.
?
Matches the preceding subexpression 0 or one time. For example, "Do (es)?" can match "do" in "do" or "does".? Equivalent to {0,1}.
N
N is a non-negative integer. Matches the determined n times. For example, ' o{2} ' cannot match ' o ' in ' Bob ', but can match two o in ' food '.
{N,}
N is a non-negative integer. Matches at least n times. For example, ' o{2,} ' cannot match ' o ' in ' Bob ', but can match all O. ' O{1 in ' Foooood ', which is equivalent to ' o+ '. ' O{0,} ' is equivalent to ' o* '.
{N,m}
Both M and n are non-negative integers, where n

Regular expression character meaning