Overview of Regular Expression!
2018-03-31
Base elements
- literal characters,(eg.
abc
) - meta characters,(eg.
.
)
note:all valid regex is composed by printable ascii characters
reducing rules
position
- anchor,(eg.
$
) - lookground,(eg.``)
- anchor,(eg.
set
- character class,(eg.
[0-9]
) - shorthand,(eg.
\d
) - unicode properties,(eg.
\p{L}
) - dot match,(eg.
.
)
- character class,(eg.
escape character
- non-printable characters,(eg.
\t
) - literal meta characters,(eg.
\\
) - non ascii characters,(eg.
\uFFFF
)
- non-printable characters,(eg.
logic
- alternation,(eg.
a|b
) - repetition(greedy,lazy),(eg.
[0-9]+
)
- alternation,(eg.
grouping and caturing
- group,(eg.
set(Value)?
) - group without caturing,((eg.
set(?:Value)?
) - back reference,(eg.
([abc])=\1
) - named group,(eg.
(?<mygroup>[abc])=\k<mygroup>
)
- group,(eg.