Regex
Regular expressions
MetaCharacters (Need to be escaped)
. ^ $ * + ? { } [ ] \ | ( )
Characters
. - Any Character Except New Line
\d - Digit (0-9)
\D - Not a Digit (0-9)
\w - Word Character (a-z, A-Z, 0-9, _)
\W - Not a Word Character
\s - Whitespace (space, tab, newline)
\S - Not Whitespace (space, tab, newline)
Character Classes
[] - Matches Characters in brackets
[^ ] - Matches Characters NOT in brackets
[a-z] - Any lowercase character between a and z
[A-Z] - Any UPPERCASE character between A and Z
Quantifiers
* - 0 or More
+ - 1 or More
? - 0 or One
{3} - Exact Number
{3,4} - Range of Numbers (Minimum, Maximum)
{3,} - At least 3
Anchors & Boundaries
\b - Word Boundary
\B - Not a Word Boundary
^ - Beginning of a String
$ - End of a String
Logic
| - Either Or
( ) - Group
\1 - Contents of group 1
White-space
\t - Tab
\r - Carriage return
\n - New line
Snippets
Markdown link pattern
\[([^\]]+)\]\(([^\)]+)\)