(?<= ) -> Positive lookbehind assertion which asserts that the character going to be matched must be preceded by a space character. (?<!, ) -> Negative lookbehind which asserts that the character going to be matched must not be preceded by a ,<space> characters. " -> match the doub...
The circumflex character ( ’^’ ), when taken as a special char- acter, does not match the beginning of string. REG_NOTEOL 设定$作为指定的字符,不用于匹配字符串尾部 The dollar sign ( ’$’ ), when taken as a special character, does not match the end of string. The following constant...
首先，正则表达式本身是不正确的：
Adding a pattern inside a character class (not allowed for RegExp instances since their top-level syntax context doesn't match). When you don't want the pattern to specify its own, local flags. Composing a dynamic number of strings escaped via regex interpolation. Dynamically adding back...
(?:https?\:|^|\s) - non-capturing group. It matches but does not capture a substring that is preceded by one of the following: https, http, start of string (^), a whitespace character (\s). The last two items are included to handle protocol-relative URLs like "//google.com". ...
(?:.*\S)?Optionally match until a non whitespace character (?:Non capture group for the alternatives \sMatch a single whitespace char [A-Ga-g][b#mM]?Match a char in the range of A-G or a-g, optionally match one ofb#mM \s\s?Match 1 or 2 whitespace chars ...
error_range-- the expression contained an invalid character range specifier error_space-- parsing a regular expression failed because there were not enough resources available error_stack-- an attempted match failed because there was not enough memory available ...
These stand for the character classes defined inwctype(3). A locale may provide others. A character class may not be used as an endpoint of a range. There are two special cases(!) of bracket expressions: the bracket expressions `[[:<:]]' and `[[:>:]]' match the null string at ...
The funcions include test, match, matchAll, search, and replace. The following table shows some regular expressions: RegexMeaning . Matches any single character. ? Matches the preceding element once or not at all. + Matches the preceding element once or more times. * Matches the preceding ...
\f ASCII Formfeed \n ASCII Linefeed \r ASCII Carriage return \t ASCII Tab \v ASCII Vertical tab \\ A single backslash \xHH Two digit hexadecimal character goes here \OOO Three digit octal char (or just use an initial zero, e.g. \0, \09) \DD Decimal number 1 to 99, match previ...