| Element |
Short Description |
| \ |
Forces special characters to be treated as ordinary characters |
| ^ |
Indicates the beginning of the pattern (i.e., forces checking from the first character) |
| $ |
Indicates the end of the pattern (i.e., forces checking until the last character) |
| * |
Used when the preceding character or group may occur zero or more times |
| + |
Used when the preceding character or group may occur one or more times |
| ? |
Used when the preceding character or group may occur zero or one time |
| . |
Represents any single character |
| [abc] |
Represents any single character within the brackets |
| [^abc] |
Represents any single character not within the brackets |
| [a-z] |
Represents any single character within the specified range |
| [^a-z] |
Represents any single character not within the specified range |
| x|y |
Represents either "x" or "y" |
| (pattern) |
Represents a group |
| (?<name>pattern) |
Creates a named group |
| {n} |
Represents when the preceding character or group occurs exactly "n" times |
| {n,} |
Represents when the preceding character or group occurs "n" or more times |
| {n,m} |
Represents when the preceding character or group occurs at least "n" and at most "m" times |
| (?=…) |
Positive lookahead (requires a specific character or text to be present in the search context) |
| (?!…) |
Negative lookahead (requires a specific character or text to be absent in the search context) |
| (?<!-)\d |
Negative lookahead (Represents a digit not preceded by a negative sign) |
| (?<=-)\d |
Positive lookahead (Represents a digit preceded by a negative sign) |
| \b |
Represents the boundary between a word character and a non-word character |
| \B |
Represents a position that is not a word boundary |
| \d |
Represents a digit |
| \D |
Represents a non-digit character |
| \n or \r\n |
Represents a new line |
| \s |
Represents a whitespace character |
| \S |
Represents a non-whitespace character |
| \t |
Represents a tab |
| \w |
Represents a word character, including "_" but excluding other symbols |
| \W |
Represents a non-word character, excluding "_" but including other symbols |