Token | Meaning | | Token | Meaning |
/ | Start and end of Ruby regular expression |
| \ / | Literal / |
^ | Start of line |
| \^ | Literal ^ |
$ | End of line |
| \$ | Literal $ |
\A | Start of input string |
| A | Literal A |
\Z | End of input string |
| Z | Literal Z |
\b | Word boundary |
| b | Literal b |
\B | Non-word boundary |
| B | Literal B |
[a-z] | Any lower case letter |
| \[ | Literal [ |
[A-Z] | Any upper case letter |
| \] | Literal ] |
[^a-z] | Any non-lower case letter |
| - | Literal - |
[^A-Z] | Any non-upper case letter |
| \\ | Literal \ |
\d | Any digit; same as [0-9] |
| d | Literal d |
\D | Any non-digit; same as [^0-9] |
| D | Literal D |
\w | Any word character; same as [A-Za-z0-9] |
| w | Literal w |
\W | Any non-word character; same as [^A-Za-z0-9] |
| W | Literal W |
\s | Any whitespace character; same as [ \n\r\f\t\v] |
| s | Literal s |
\S | Any non-whitespace character; same as [^ \n\r\f\t\v] |
| S | Literal S |
( ) | Grouping |
| \( \) |
Literal ( ) |
| | Or |
| \| | Literal | |
. | Any character |
| \. | Literal . |
? | 0 or 1 occurrences |
| \? | Literal ? |
* | 0 or more occurrences |
| \* | Literal * |
+ | 1 or more occurrences |
| \+ | Literal + |
{n} | Exactly n occurrences |
| \{ | Literal { |
{n,m} | Between n and m occurrences, inclusive |
| \} | Literal } |