| |
| . |
any character |
| ^a |
begins with a |
| a$ |
ends with a |
| a+ |
at least one
a |
| a? |
zero or one a |
| \n |
new line |
| \t |
tab |
| \ |
escape |
| (ab) |
ab grouped |
| a|b |
a or b |
| a{2} |
aa |
| a{1,} |
a, aa, aaa, etc. |
| a{1,3} |
a, aa, aaa |
| [a-z] |
any lowercase
letters |
| [A-Z] |
any uppercase
letters |
| [0-9] |
any digit |
|