| 123… |
Digits |
| \d |
Any Digit |
| \D |
Any Non-digit character |
| . |
Any Character |
| . |
Period |
| [abc] |
Only a, b, or c |
| abc |
Not a, b, nor c |
| [a-z] |
Characters a to z |
| [0-9] |
Numbers 0 to 9 |
| \w |
Any Alphanumeric character |
| \W |
Any Non-alphanumeric character |
| {m} |
m Repetitions |
| {m,n} |
m to n Repetitions |
| * |
Zero or more repetitions |
| + |
One or more repetitions |
| ? |
Optional character |
| \s |
Any Whitespace |
| \S |
Any Non-whitespace character |
| ^…$ |
Starts and ends |
| (…) |
Capture Group |
| (a(bc)) |
Capture Sub-group |
| (.*) |
Capture all |
| (abc\ |
def) |
Matches abc or def |