This is an old revision of the document!
일부 내용은 손에 잡히는 정규 표현식에서 발췌
수량자.
과하게 일치하는 상황 방지
| Greedy Qualifier | Lazy Qualifier |
|---|---|
| * | *? |
| + | +? |
| {n,} | {n,}? |
(?i)<b>.*</b>
(?i)<b>.*?</b>괄호로 감싼 하위 표현식을 참조하는 정규 표현식. $1~n 으로 표현. (일부 언어는 $대신 /을 사용하기도 한다.)
변수와 비슷.
String eg1 = "Hello, [email protected] is my email address."; String result1 = eg1.replaceAll("(\\w+[\\w.]*@[\\w.]+\\.\\w+)", "<a href=\"$1\">$1</href>"); System.out.println(result1); // Hello, <a href="[email protected]">[email protected]</href> is my email address. String eg2 = "031-123-1234"; String result2 = eg2.replaceAll("(\\d{3})(-)(\\d{3})(-)(\\d{4})", "($1) $3-$5"); System.out.println(result2); // (031) 123-1234
일치하는 영역을 제외하고, 일치하는 영역 기준으로 이전 혹은 이후 값을 반환
전방 탐색. ?=
.+(?=:)
http://www.google.com
https://mail.google.com
ftp://ftp.xxx.xyz
후방 탐색. ?<=
(?<=\$)[0-9.]+
A11 : $23.34
B22 : $5.31
Total items found : 2
https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html
Pattern p = Pattern.compile("^REGULAR_EXPRESSION$", Pattern.CASE_INSENSITIVE); // regex, pattern
Matcher m = p.matcher(STRING);
boolean b = m.matches();
Pattern.CASE_INSENSITIVE (?i) Pattern.COMMENTS (?x) Pattern.MULTILINE (?m) Pattern.DOTALL (?s) Pattern.LITERAL None Pattern.UNICODE_CASE (?u) Pattern.UNIX_LINES (?d)
\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} Punctuation: One of !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~
\p{Graph} A visible character: [\p{Alnum}\p{Punct}]
\p{Print} A printable character: [\p{Graph}\x20]
\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]
^(02|0[3-6]{1}[1-5]{1})-?[0-9]{3,4}-?[0-9]{4}$ //지역번호-xxx(x)-xxxx
^(15(44|77|88|99)|1644)-?[0-9]{4}$ //15xx/1644-xxxx
String str = "(int a, int b)";
Pattern p = Pattern.compile("\\((.*?)\\)");
Matcher m = p.matcher(str);
while(m.find())
System.out.println(m.group(1));