As we have seen from the preceding examples, certain character classes, such as digits [0-9] or word characters [0-9A-Za-z_], are used in most regex patterns. The Java language, like all regular expression flavors, provides convenient predefined character classes for these character classes. Here is the list:
| Shorthand Class | Meaning | Character Class |
| d | A digit 0-9 | [0-9] |
| D | A non-digit | [^d] |
| w | A word character | [a-zA-Z0-9_] |
| W | A non-word character | [^w] |
| s | A whitespace character, including line break | [ fx0B] |
| S | A non-whitespace chacracter | [^s] |
| h | A horizontal whitespace character | [ xA0u1680u180eu2000-u200au202fu205fu3000] |
| H | A non-horizontal whitespace character | [^h] |
| v | A vertical whitespace character | [ x0Bf x85u2028u2029] |
| V | A non-vertical whitespace character | [^v] |