| Category |
Symbol |
Name |
Meaning |
Example |
Matches
|
| 1. Wildcards & Character Classes
|
| Matching Characters
|
(text) |
Literal |
Matches exact text |
cat |
"cat"
|
. |
Dot |
Matches any single character (except newline) |
h.t |
"hat", "hot"
|
[ ] |
Brackets |
List of allowed characters |
b[ai]t |
"bat", "bit"
|
[^ ] |
Negation |
Matches anything NOT in the list |
[^a] |
Any char except 'a'
|
\d |
Digit |
Any number 0-9 |
\d\d |
"42", "99"
|
\w |
Word Char |
Letter, number, or underscore |
\w+ |
"User_1"
|
\s |
Space |
Whitespace (space, tab, enter) |
A\sB |
"A B"
|
| 2. Quantifiers (How Many?)
|
| Counting
|
* |
Star |
0 or more times |
go*d |
"gd", "god"
|
+ |
Plus |
1 or more times |
go+d |
"god", "good"
|
? |
Question |
0 or 1 time (Optional) |
colou?r |
"color", "colour"
|
{n} |
Exact Count |
Matches exactly n times |
\d{3} |
"123"
|
{n,} |
Min Count |
Matches n or more times |
\d{3,} |
"123", "12345"
|
{n,m} |
Range |
Matches between n and m times |
\d{2,4} |
"12", "1234"
|
.*? |
Lazy Match |
Matches as little as possible |
<.*?> |
Stops at first matching char
|
| 3. Anchors & Boundaries (Where?)
|
| Positioning
|
^ |
Caret |
Start of string/line |
^The |
Starts with "The"
|
$ |
Dollar |
End of string/line |
end$ |
Ends with "end"
|
\b |
Word Boundary |
The edge of a word (start or end) |
\bcat\b |
"cat" (not "scat")
|
| 4. Groups & Logic
|
| Logic
|
|
Pipe |
OR logic (Alternative) |
dog |
"cat" or "dog"
|
(...) |
Group |
Groups characters or captures them |
b)c |
"ac" or "bc"
|
| 5. Special Characters
|
| Escaping |
\ |
Backslash |
Treats special characters as text |
\. |
"." (actual dot)
|