Examples
/ hello /hello/ [hH]ello /hello wello Hello
[] is a
Character Set
/ [^hH]ello /hello wello Hello/ [a-z]ello /hello wello Hello
[A-z] is a ‘Range’ [A-z] == [a-zA-Z]
/ [0-9]+/1 1Hello 123 12
/ [0-9]{2, 3} /1Hello 123 12
{} means how many times needed to match {2, } goes from 2 matches to infinity
Metacharacters
- \d match any digit character
- \w matches any word character (included numbers,
_,,) - \s match whitespace (space, tab)
- \t match tab
Special Characters
- + The one or more quantifier
- \ The escape character
- [] The character set
- [^] The negate symbol in a character set
- ? Zero-or-one quantifier
- . Any character except the newline
- * Zero-or-more
- ^ Start
- & End
- | Or
- () Separate entity
Flags
/gdon’t stop after first match/icase insenstive match