Regular Expression Metacharacters
Metacharacters are characters with a special meaning.
They can be used to match digts, words, spaces, and more:
// Match words
const pattern = /\w/;JavaScript Regex Metacharacters
| Meta | Description |
|---|---|
| \d | Matches Digits |
| \D | Matches None Digits |
| \w | Matches alphanumeric Word characters |
| \W | Matches None alphanumeric Word characters |
| \s | Matches Spaces |
| \S | Matches None Spaces |
| \ddd | Matches characters by the Octal numer ddd |
| \xhh | Matches characters by the HexadecimaL number hh |
| \uhhhh | Matches Unicode characters by the hex number hhhh |
RegExp \d (digits) Metacharacter
The \d metacharacter matches digits.
Example
let text = "Give 100%!";
const pattern = /\d/g;
let result = text.match(pattern);RegExp \D Metacharacter
The \D metacharacter matches non-digit characters.
Example
let text = "Give 100%!";
const pattern = /\D/g;
let result = text.match(pattern);RegExp \w (word) Metacharacter
The \w metacharacter matches word characters.
A word character is a character a-z, A-Z, 0-9, including _ (underscore).
Example
let text = "Give 100%!";
const pattern = /\w/g;
let result = text.match(pattern);RegExp \W Metacharacter
The \W metacharacter matches non-word characters.
A word character is a character a-z, A-Z, 0-9, including _ (underscore).
Example
let text = "Give 100%!";
const pattern = /\W/g;
let result = text.match(pattern);The \s (space) Metacharacter
The \s metacharacter matches whitespace characters like space, tab, and newline.
Example
let text = "Is this all there is?";
const pattern = /\s/g;
let result = text.match(pattern);RegExp \xhh (hexadecimal)
\xhh matches characters by the hexadecimal number hh.
Runnable example
let text = "Visit ExampleSite. Hello World!";
let pattern = /\x6F/g;
let result = text.replace(pattern, "*");RegExp \uhhhh (unicode hex)
\uhhhh matches a Unicode character by the hex number hhhh.
Example
let text = "Visit ExampleSite. Hello World!";
const pattern = /\u0057/g;
let result = text.match(pattern);Regular Expression Methods
Regular Expression Search and Replace can be done with different methods.
String Methods
| Method | Description |
|---|---|
| match( regex ) | Returns an Array of results |
| matchAll( regex ) | Returns an Iterator of results |
| replace( regex ) | Returns a new String |
| replaceAll( regex ) | Returns a new String |
| search( regex ) | Returns the index of the first match |
| split( regex ) | Returns an Array of results |
RegExp Methods
| Method | Description |
|---|---|
| regex .exec() | Returns an Iterator of results |
| regex .test() | Returns true or false |
See Also
JavaScript RegExp Character Classes
JavaScript RegExp Assertions
JavaScript RegExp Quantifiers
JavaScript RegExp Patterns
JavaScript RegExp Objects
JavaScript RegExp Methods