- Tools
- Cheatsheet
- Examples
- Programming Languages
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Online Tool
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grep -P "<regex>" <path> # omit leading & trailing '/' from regex
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sag "<regex>" <path> # omit leading & trailing '/' from regex
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VS Code: Ctrl+F > Alt+R
RegEx |
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 |
RegEx |
Description |
* |
0 or More |
+ |
1 or More |
? |
0 or One |
{3} |
Exact Number |
{3,4} |
Range of Numbers (Minimum, Maximum) |
ninja # 'ninja'
^ninja$ # exactly 'ninja' and nothing else
[ng]inja # 'ninja' or 'ginja'
ninja[1-9] # 'ninja1' to 'ninja9'
[^n]inja # every '_inja' except 'ninja'
[0-9]+ # multiple digits
a{3} # 3 'a's
[a-zA-Z]{5,8} # 5 to 8 characters
Optional/Alternate Matches
(cat|dog|bird) # 'cat' or 'dog' or 'bird'
M(r|s|rs)\.? # 'Mr/Mr./Ms/Ms./Mrs/Mrs.'
// these two are equivalent
const reg1 = /[a-z]/i
const reg2 = new RegExp(/[a-z]/, 'i')
reg1.test("b") // true
reg2.test("3") // false
const text = "http://www.google.com";
const regex = /https?://(www\.)?(\w+)(\.\w+)/
const [whole, www, domain, extension] = text.match(regex)