{"id":303,"date":"2011-08-02T12:53:16","date_gmt":"2011-08-02T12:53:16","guid":{"rendered":"http:\/\/www.extradrm.com\/?p=303"},"modified":"2013-05-17T10:35:57","modified_gmt":"2013-05-17T08:35:57","slug":"c-regular-expressions-guide","status":"publish","type":"post","link":"https:\/\/www.extradrm.com\/?p=303","title":{"rendered":"C# Regular Expressions Guide"},"content":{"rendered":"
Guide for C# regular expressions metacharacters, operators, quantifiers etc<\/div>\n

 <\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\n
Character<\/div>\n<\/th>\n
Description<\/th>\n<\/tr>\n
<\/td>\nMarks the next character as either a special character or escapes a literal. For example, “n” matches the character “n”. “n” matches a newline character. The sequence “\\” matches “” and “(” matches “(“.Note: double quotes may be escaped by doubling them: “<a href=””…>”<\/td>\n<\/tr>\n
^ <\/strong><\/td>\nDepending on whether the MultiLine option is set, matches the position before the first character in a line, or the first character in the string.<\/td>\n<\/tr>\n
$ <\/strong><\/td>\nDepending on whether the MultiLine option is set, matches the position after the last character in a line, or the last character in the string.<\/td>\n<\/tr>\n
* <\/strong><\/td>\nMatches the preceding character zero or more times. For example, “zo*” matches either “z” or “zoo”.<\/td>\n<\/tr>\n
+ <\/strong><\/td>\nMatches the preceding character one or more times. For example, “zo+” matches “zoo” but not “z”.<\/td>\n<\/tr>\n
? <\/strong><\/td>\nMatches the preceding character zero or one time. For example, “a?ve?” matches the “ve” in “never”.<\/td>\n<\/tr>\n
.<\/strong><\/td>\nMatches any single character except a newline character.<\/td>\n<\/tr>\n
(pattern) <\/strong><\/td>\nMatches pattern<\/em> and remembers the match. The matched substring can be retrieved from the resulting Matches<\/strong> collection, using Item [0]…[n]<\/strong>. To match parentheses characters ( ), use “(” or “)”.<\/td>\n<\/tr>\n
(?<name>pattern) <\/strong><\/td>\nMatches pattern<\/em> and gives the match a name.<\/td>\n<\/tr>\n
(?:pattern) <\/strong><\/td>\nA non-capturing group<\/td>\n<\/tr>\n
(?=…) <\/strong><\/td>\nA positive lookahead<\/td>\n<\/tr>\n
(?!…) <\/strong><\/td>\nA negative lookahead<\/td>\n<\/tr>\n
(?<=…) <\/strong><\/td>\nA positive lookbehind .<\/td>\n<\/tr>\n
(?<!…) <\/strong><\/td>\nA negative lookbehind .<\/td>\n<\/tr>\n
x|y<\/strong><\/td>\nMatches either x<\/em> or y<\/em>. For example, “z|wood” matches “z” or “wood”. “(z|w)oo” matches “zoo” or “wood”.<\/td>\n<\/tr>\n
{n<\/em>}<\/strong><\/td>\nn<\/em> is a non-negative integer. Matches exactly n<\/em> times. For example, “o{2}” does not match the “o” in “Bob,” but matches the first two o’s in “foooood”.<\/td>\n<\/tr>\n
{n<\/em>,} <\/strong><\/td>\nn<\/em> is a non-negative integer. Matches at least n<\/em> times. For example, “o{2,}” does not match the “o” in “Bob” and matches all the o’s in “foooood.” “o{1,}” is equivalent to “o+”. “o{0,}” is equivalent to “o*”.<\/td>\n<\/tr>\n
{<\/strong>n<\/em>,<\/strong>m<\/em>}<\/strong><\/td>\nm<\/em> and n<\/em> are non-negative integers. Matches at least n<\/em> and at most m<\/em> times. For example, “o{1,3}” matches the first three o’s in “fooooood.” “o{0,1}” is equivalent to “o?”.<\/td>\n<\/tr>\n
[<\/strong>xyz<\/em>]<\/strong><\/td>\nA character set. Matches any one of the enclosed characters. For example, “[abc]” matches the “a” in “plain”.<\/td>\n<\/tr>\n
[^<\/strong>xyz<\/em>]<\/strong><\/td>\nA negative character set. Matches any character not enclosed. For example, “[^abc]” matches the “p” in “plain”.<\/td>\n<\/tr>\n
[<\/strong>a-z<\/em>]<\/strong><\/td>\nA range of characters. Matches any character in the specified range. For example, “[a-z]” matches any lowercase alphabetic character in the range “a” through “z”.<\/td>\n<\/tr>\n
[^<\/strong>m-z<\/em>]<\/strong><\/td>\nA negative range characters. Matches any character not in the specified range. For example, “[m-z]” matches any character not in the range “m” through “z”.<\/td>\n<\/tr>\n
b <\/strong><\/td>\nMatches a word boundary, that is, the position between a word and a space. For example, “erb” matches the “er” in “never” but not the “er” in “verb”.<\/td>\n<\/tr>\n
B <\/strong><\/td>\nMatches a non-word boundary. “ea*rB” matches the “ear” in “never early”.<\/td>\n<\/tr>\n
d <\/strong><\/td>\nMatches a digit character. Equivalent to [0-9].<\/td>\n<\/tr>\n
D <\/strong><\/td>\nMatches a non-digit character. Equivalent to [^0-9].<\/td>\n<\/tr>\n
f <\/strong><\/td>\nMatches a form-feed character.<\/td>\n<\/tr>\n
k <\/strong><\/td>\nA back-reference to a named group.<\/td>\n<\/tr>\n
n <\/strong><\/td>\nMatches a newline character.<\/td>\n<\/tr>\n
r <\/strong><\/td>\nMatches a carriage return character.<\/td>\n<\/tr>\n
s <\/strong><\/td>\nMatches any white space including space, tab, form-feed, etc. Equivalent to “[\u00a0fnrtv]”.<\/td>\n<\/tr>\n
S <\/strong><\/td>\nMatches any nonwhite space character. Equivalent to “[^\u00a0fnrtv]”.<\/td>\n<\/tr>\n
t <\/strong><\/td>\nMatches a tab character.<\/td>\n<\/tr>\n
v <\/strong><\/td>\nMatches a vertical tab character.<\/td>\n<\/tr>\n
w <\/strong><\/td>\nMatches any word character including underscore. Equivalent to “[A-Za-z0-9_]”.<\/td>\n<\/tr>\n
W <\/strong><\/td>\nMatches any non-word character. Equivalent to “[^A-Za-z0-9_]”.<\/td>\n<\/tr>\n
num <\/strong><\/td>\nMatches num<\/em>, where num<\/em> is a positive integer. A reference back to remembered matches. For example, “(.)1” matches two consecutive identical characters.<\/td>\n<\/tr>\n
n<\/em><\/strong><\/td>\nMatches n<\/em>, where n<\/em> is an octal escape value. Octal escape values must be 1, 2, or 3 digits long. For example, “11” and “\ufffd11” both match a tab character. “\ufffd011” is the equivalent of “\ufffd01” & “1”. Octal escape values must not exceed 256. If they do, only the first two digits comprise the expression. Allows ASCII codes to be used in regular expressions.<\/td>\n<\/tr>\n
xn<\/em><\/strong><\/td>\nMatches n<\/em>, where n<\/em> is a hexadecimal escape value. Hexadecimal escape values must be exactly two digits long. For example, “x41” matches “A”. “x041” is equivalent to “x04” & “1”. Allows ASCII codes to be used in regular expressions.<\/td>\n<\/tr>\n
un<\/em><\/strong><\/td>\nMatches a Unicode character expressed in hexadecimal notation with exactly four numeric digits. “u0200” matches a space character.<\/td>\n<\/tr>\n
A<\/strong><\/td>\nMatches the position before the first character in a string. Not affected by the MultiLine setting<\/td>\n<\/tr>\n
Z<\/strong><\/td>\nMatches the position after the last character of a string. Not affected by the MultiLine setting.<\/td>\n<\/tr>\n
G<\/strong><\/td>\nSpecifies that the matches must be consecutive, without any intervening non-matching characters.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

Guide for C# regular expressions metacharacters, operators, quantifiers etc   Character Description Marks the next character as either a special character or escapes a literal. For example, “n” matches the character “n”. “n” matches...<\/p>\n","protected":false},"author":1,"featured_media":2850,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[22],"tags":[140,141,142],"youtube_video":null,"_links":{"self":[{"href":"https:\/\/www.extradrm.com\/index.php?rest_route=\/wp\/v2\/posts\/303"}],"collection":[{"href":"https:\/\/www.extradrm.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.extradrm.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.extradrm.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.extradrm.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=303"}],"version-history":[{"count":0,"href":"https:\/\/www.extradrm.com\/index.php?rest_route=\/wp\/v2\/posts\/303\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.extradrm.com\/index.php?rest_route=\/wp\/v2\/media\/2850"}],"wp:attachment":[{"href":"https:\/\/www.extradrm.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=303"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.extradrm.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=303"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.extradrm.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=303"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}