A character class matches any one of a set of characters. Character classes include the language elements listed in table 1.
Character class |
Description |
[ character_group ] |
Matches any single character in character_group. By default, the match is case-sensitive. |
[^ character_group ] |
Negation: Matches any single character that is not in character_group. By default, characters in character_group are case-sensitive. |
[ first - last ] |
Character range: Matches any single character in the range from first to last. |
. |
Wildcard: Matches any single character except \n. To match a literal period character (. or \u002E), you must precede it with the escape character (\.). |
\p{ name } |
Matches any single character in the Unicode general category or named block specified by name. |
\P{ name } |
Matches any single character that is not in the Unicode general category or named block specified by name. |
\w |
Matches any word character. |
\W |
Matches any non-word character. |
\s |
Matches any white-space character. |
\S |
Matches any non-white-space character. |
\d |
Matches any decimal digit. |
\D |
Matches any character other than a decimal digit. |
Table 1: character classes
Pattern |
Matches |
[ae] |
"a" in "gray" "a", "e" in "lane" |
[^aei] |
"r", "g", "n" in "reign" |
[A-Z] |
"A", "B" in "AB123" |
a.e |
"ave" in "nave" "ate" in "water" |
\p{Lu} \p{IsCyrillic} |
"C", "L" in "City Lights" "Д", "Ж" in "ДЖem" |
\P{Lu} \P{IsCyrillic} |
"i", "t", "y" in "City" "e", "m" in "ДЖem" |
\w |
"I", "D", "A", "1", "3" in "ID A1.3" |
\W |
" ", "." in "ID A1.3" |
\w\s |
"D " in "ID A1.3" |
\s\S |
" _" in "int __ctr" |
\d |
"4" in "4 = IV" |
\D |
" ", "=", " ", "I", "V" in "4 = IV" |
Table 2: Examples for character classes
