Used to match the string in a sequence of chars. Regular expression is case sensitive.
- this is the simplest of all searches. to search ABC just do ABC.
- there are some reserved keywords in Regular Expression which has special meaning. like . . so to search for a . we can not just write it like that. we need to escape it. like \. .
- other special chars in regular expression are - .[{()^$|?*+
Pattern | Description |
---|---|
. | 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) |
\b | Word Boundary |
\B | Not a Word Boundary |
^ | Beginning of a String |
$ | End of a String |
[] | Matches Characters in brackets |
[^ ] | Matches Characters NOT in brackets |
| | Either Or |
( ) | Group |
Pattern | Description |
---|---|
* | 0 or More |
+ | 1 or More |
? | 0 or One |
{3} | Exact Number |
{3,4} | Range of Numbers (Minimum, Maximum) |