Regular-Expression
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Beschreibung
Reguläre Ausdrücke sind Muster, mit denen man den Aufbau von Zeichenketten beschreibt.
Characters
Ausdruck | Bedeutung |
---|---|
x
|
The character x |
\\
|
The backslash character |
\0n
|
The character with octal value 0n (0 <= n <= 7) |
\0nn
|
The character with octal value 0nn (0 <= n <= 7) |
\0mnn
|
The character with octal value 0mnn (0 <= m <= 3, 0 <= n <= 7) |
\xhh
|
The character with hexadecimal value 0xhh |
\uhhhh
|
The character with hexadecimal value 0xhhhh |
\t
|
The tab character ('\u0009') |
\n
|
The newline (line feed) character ('\u000A') |
\r
|
The carriage-return character ('\u000D') |
\f
|
The form-feed character ('\u000C') |
\a
|
The alert (bell) character ('\u0007') |
\e
|
The escape character ('\u001B') |
\cx
|
The control character corresponding to x |
Character classes
Ausdruck | Bedeutung |
---|---|
[abc]
|
a, b, or c (simple class) |
[^abc]
|
Any character except a, b, or c (negation) |
[a-zA-Z]
|
a through z or A through Z, inclusive (range) |
[a-d[m-p]]
|
a through d, or m through p: [a-dm-p] (union) |
[a-z&&[def]]
|
d, e, or f (intersect1) |
[a-z&&[^bc]]
|
a through z, except for b and c: [ad-z] (subtraction) |
[a-z&&[^m-p]]
|
a through z, and not m through p: [a-lq-z](subtraction) |
Predefined character classes
Ausdruck | Bedeutung |
---|---|
.
|
Any character |
\d
|
A digit: [0-9] |
\D
|
A non-digit: [^0-9] |
\s
|
A whitespace character: [ \t\n\x0B\f\r] |
\S
|
A non-whitespace character: [^\s] |
\w
|
A word character: [a-zA-Z_0-9] |
\W
|
A non-word character: [^\w] |
POSIX character classes (US-ASCII only)
Ausdruck | Bedeutung |
---|---|
\p{Lower}
|
A lower-case alphabetic character: [a-z] |
\p{Upper}
|
An upper-case alphabetic character:[A-Z] |
\p{ASCII}
|
All ASCII:[\x00-\x7F] |
\p{Alpha}
|
An alphabetic character:[\p{Lower}\p{Upper}] |
\p{Digit}
|
A decimal digit: [0-9] |
\p{Alnum}
|
An alphanumeric character:[\p{Alpha}\p{Digit}] |
\p{Punct}
|
}~ |
\p{Graph}
|
A visible character: [\p{Alnum}\p{Punct}] |
\p{Print}
|
A printable character: [\p{Graph}] |
\p{Blank}
|
A space or a tab: [ \t] |
\p{Cntrl}
|
A control character: [\x00-\x1F\x7F] |
\p{XDigit}
|
A hexadecimal digit: [0-9a-fA-F] |
\p{Space}
|
A whitespace character: [ \t\n\x0B\f\r] |
Classes for Unicode blocks and categories
Ausdruck | Bedeutung |
---|---|
\p{InGreek}
|
A character in the Greek block (simple block) |
\p{Lu}
|
An uppercase letter (simple category) |
\p{Sc}
|
A currency symbol |
\P{InGreek}
|
Any character except one in the Greek block (negation) |
[\p{L}&&[^\p{Lu}]]
|
Any letter except an uppercase letter (subtraction) |
Boundary matchers
Ausdruck | Bedeutung |
---|---|
^
|
The beginning of a line |
$
|
The end of a line |
\b
|
A word boundary |
\B
|
A non-word boundary |
\A
|
The beginning of the input |
\G
|
The end of the previous match |
\Z
|
The end of the input but for the final terminator, if any |
\z
|
The end of the input |
Greedy quantifiers
Ausdruck | Bedeutung |
---|---|
X?
|
X, once or not at all |
X*
|
X, zero or more times |
X+
|
X, one or more times |
X{n}
|
X, exactly n times |
X(n,}
|
X, at least n times |
X{n,m}
|
X, at least n but not more than m times |
Reluctant quantifiers
Ausdruck | Bedeutung |
---|---|
X??
|
X, once or not at all |
X*?
|
X, zero or more times |
X+?
|
X, one or more times |
X{n}?
|
X, exactly n times |
X(n,}?
|
X, at least n times |
X{n,m}?
|
X, at least n but not more than m times |
Possessive quantifiers
Ausdruck | Bedeutung |
---|---|
X?+
|
X, once or not at all |
X*+
|
X, zero or more times |
X++
|
X, one or more times |
X{n}+
|
X, exactly n times |
X(n,}+
|
X, at least n times |
X{n,m}+
|
X, at least n but not more than m times |
Logical operators
Ausdruck | Bedeutung |
---|---|
XY
|
X followed by Y |
Y | Either X or Y |
(X)
|
X, as a capturing group |
Back references
Ausdruck | Bedeutung |
---|---|
$n
|
Whatever the n-th capturing group matched |
Quotation
Ausdruck | Bedeutung |
---|---|
\
|
Nothing, but quotes the following character |
\Q
|
Nothing, but quotes all characters until \E |
\E
|
Nothing, but ends quoting started by \Q |
Special constructs (non-capturing)
Ausdruck | Bedeutung |
---|---|
(?:X)
|
X, as a non-capturing group |
(?idmsux-idmsux)
|
Nothing, but turns match flags on - off |
(?idmsux-idmsux:X)
|
X, as a non-capturing group with the given flags on - off |
(?=X)
|
X, via zero-width positive lookahead |
(?!X)
|
X, via zero-width negative lookahead |
(?<=X)
|
X, via zero-width negative lookahead |
(?>X)
|
X, as an independent, non-capturing group |
Embedded flag expressions
Ausdruck | Bedeutung |
---|---|
(?u)
|
Pattern.UNICODE_CASE |
(?s)
|
Pattern.DOTALL |
(?m)
|
Pattern.MULTILINE |
(?i)
|
Pattern.CASE_INSENSITIVE |
(?x)
|
Pattern.COMMENTS |
(?d)
|
Pattern.UNIX_LINES |
---
|
Pattern.CANON_EQ (not available) |