정규식 - Characters

  □ Literal characters

Regex:  /car/

String: "car"

Regex:  /car/

String: "carnival"

Case-sensitivity matters

Regex:  /car/

String: "Carnival"

Regex:  /car/i

String: "Carnival"

Regex:  /Car/i

String: "carnival"

Whitespace matters

Regex:  /car/

String: "c a r"

Global modifier

Regex:  /zz/

String: "pizzazz"

- 맨 왼쪽, 맨 처음만 선택됨이 디폴트.

Regex:  /zz/g

String: "pizzazz"

- g모드에서 전체 매칭.

Regex:  /cat/

String: "The cow, camel, and cat communicated."

Regex:  /cat/g

String: "The cow, camel, and cat communicated."

  □ Metacharacters

종류 : \ . * + - {} [] ^ $ | ? ( ) : ! =

- 맥락에 따라 의미가 달라질 수 있다.

Regex: . * + [abc] ^ $ | ? (abc) \d{2,3}

  □ The wildcard metacharacter

Regex:  /h.t/ : h(글자하나)h

String: "hat hot hit heat hzt h t h#t h:t"

Regex:  /.a.a.a/

String: "banana papaya abacab"

Regex:  /a.a.a./

String: "banana papaya abacab"

Write a regex that matches all three words:

Regex:

String: "silver sliver slider"

  □ Escaping metacharacters

- 역슬래시(\) 사용해서 메타캐릭터를 피함.

Regex:  /9\.00/

String: "9.00 9500 9-00"

String: "his_export.txt her_export.txt"

Regex:  /h.._export.txt/

Regex:  /h.._export\.txt/

String: "resume1.txt resume2.txt resume3_txt.zip"

Regex:  /resume.\.txt/

Also may need to escape /

String: "/home/user/document.txt"

Regex:  //home/user/document\.txt/

Regex:  /\/home\/user\/document\.txt/

  □ Other special ch aracters

- space는 글자.

Regex:  /c a t/

String: "c a t"

- 탭은 \t

Regex:  /a\tb/

String: "a  b"

- 엔터는 \n

Regex:  /c\nd/

String: "abc

def"

0xA9 = \xA9