Character classes

## Types

<table class="standard-table">
  <thead>
    <tr>
      <th scope="col">Characters</th>
      <th scope="col">Meaning</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>
        <code>[xyz]<br />[a-c]</code>
      </td>
      <td>
        <p>
          <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_class"><strong>Character class:</strong></a>
          Matches any one of the enclosed characters. You can
          specify a range of characters by using a hyphen, but if the hyphen
          appears as the first or last character enclosed in the square brackets,
          it is taken as a literal hyphen to be included in the character class
          as a normal character.
        </p>
        <p>
          For example, <code>[abcd]</code> is the same as <code>[a-d]</code>.
          They match the "b" in "brisket", and the "c" in "chop".
        </p>
        <p>
          For example, <code>[abcd-]</code> and <code>[-abcd]</code> match the
          "b" in "brisket", the "c" in "chop", and the "-" (hyphen) in
          "non-profit".
        </p>
        <p>
          For example, <code>[\w-]</code> is the same as
          <code>[A-Za-z0-9_-]</code>. They both match the "b" in "brisket", the
          "c" in "chop", and the "n" in "non-profit".
        </p>
        <p>
          When the <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/unicodeSets"><code>unicodeSets</code></a> (<code>v</code>) flag is enabled, the character class has some additional features. See the <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_class">character class</a> reference for more information.
        </p>
      </td>
    </tr>
    <tr>
      <td>
        <p>
          <code>[^xyz]<br />[^a-c]</code>
        </p>
      </td>
      <td>
        <p>
          <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_class"><strong>Negated character class:</strong></a>
          Matches anything that is not enclosed in the square brackets. You can specify a range
          of characters by using a hyphen, but if the hyphen appears as the
          first character after the <code>^</code> or the last character enclosed in the square brackets, it is taken as
          a literal hyphen to be included in the character class as a normal
          character. For example, <code>[^abc]</code> is the same as
          <code>[^a-c]</code>. They initially match "o" in "bacon" and "h" in
          "chop".
        </p>
        <div class="notecard note">
          <p>
            <strong>Note:</strong> The ^ character may also indicate the
            <a
              href="/en-US/docs/Web/JavaScript/Guide/Regular_expressions/Assertions"
              >beginning of input</a
            >.
          </p>
        </div>
      </td>
    </tr>
    <tr>
      <td><code>.</code></td>
      <td>
        <p>
          <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Wildcard"><strong>Wildcard:</strong></a>
          Matches any single character <em>except</em> line terminators:
          <code>\n</code>, <code>\r</code>, <code>\u2028</code> or
          <code>\u2029</code>. For example, <code>/.y/</code> matches "my" and
          "ay", but not "yes", in "yes make my day", as there is no character before "y" in "yes". If the <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/dotAll"><code>dotAll</code></a> (s) flag is enabled, also matches line terminators.
          Inside a character class, the dot loses its special meaning and
          matches a literal dot.
        </p>
      </td>
    </tr>
    <tr>
      <td><code>\d</code></td>
      <td>
        <p>
          <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_class_escape"><strong>Digit character class escape:</strong></a>
          Matches any digit (Arabic numeral). Equivalent to <code>[0-9]</code>.
          For example, <code>/\d/</code> or <code>/[0-9]/</code> matches "2" in
          "B2 is the suite number".
        </p>
      </td>
    </tr>
    <tr>
      <td><code>\D</code></td>
      <td>
        <p>
          <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_class_escape"><strong>Non-digit character class escape:</strong></a>
          Matches any character that is not a digit (Arabic numeral). Equivalent
          to <code>[^0-9]</code>. For example, <code>/\D/</code> or
          <code>/[^0-9]/</code> matches "B" in "B2 is the suite number".
        </p>
      </td>
    </tr>
    <tr>
      <td><code>\w</code></td>
      <td>
        <p>
          <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_class_escape"><strong>Word character class escape:</strong></a>
          Matches any alphanumeric character from the basic Latin alphabet,
          including the underscore. Equivalent to <code>[A-Za-z0-9_]</code>. For
          example, <code>/\w/</code> matches "a" in "apple", "5" in "$5.28", "3"
          in "3D" and "m" in "Émanuel".
        </p>
      </td>
    </tr>
    <tr>
      <td><code>\W</code></td>
      <td>
        <p>
          <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_class_escape"><strong>Non-word character class escape:</strong></a>
          Matches any character that is not a word character from the basic
          Latin alphabet. Equivalent to <code>[^A-Za-z0-9_]</code>. For example,
          <code>/\W/</code> or <code>/[^A-Za-z0-9_]/</code> matches "%" in "50%"
          and "É" in "Émanuel".
        </p>
      </td>
    </tr>
    <tr>
      <td><code>\s</code></td>
      <td>
        <p>
          <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_class_escape"><strong>White space character class escape:</strong></a>
          Matches a single white space character, including space, tab, form
          feed, line feed, and other Unicode spaces. Equivalent to
          <code>[\f\n\r\t\v\u0020\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff]</code>. For example, <code>/\s\w*/</code> matches " bar" in "foo bar".
        </p>
      </td>
    </tr>
    <tr>
      <td><code>\S</code></td>
      <td>
        <p>
          <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_class_escape"><strong>Non-white space character class escape:</strong></a>
          Matches a single character other than white space. Equivalent to
          <code>[^\f\n\r\t\v\u0020\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff]</code>. For example, <code>/\S\w*/</code> matches "foo" in "foo bar".
        </p>
      </td>
    </tr>
    <tr>
      <td><code>\t</code></td>
      <td>Matches a horizontal tab.</td>
    </tr>
    <tr>
      <td><code>\r</code></td>
      <td>Matches a carriage return.</td>
    </tr>
    <tr>
      <td><code>\n</code></td>
      <td>Matches a linefeed.</td>
    </tr>
    <tr>
      <td><code>\v</code></td>
      <td>Matches a vertical tab.</td>
    </tr>
    <tr>
      <td><code>\f</code></td>
      <td>Matches a form-feed.</td>
    </tr>
    <tr>
      <td><code>[\b]</code></td>
      <td>
        Matches a backspace. If you're looking for the word-boundary assertion
        (<code>\b</code>), see
        <a
          href="/en-US/docs/Web/JavaScript/Guide/Regular_expressions/Assertions"
          >Assertions</a
        >.
      </td>
    </tr>
    <tr>
      <td><code>\0</code></td>
      <td>Matches a NUL character. Do not follow this with another digit.</td>
    </tr>
    <tr>
      <td>
        <code>\c<em>X</em></code>
      </td>
      <td>
        <p>
          Matches a control character using
          <a href="https://en.wikipedia.org/wiki/Caret_notation"
            >caret notation</a
          >, where "X" is a letter from A–Z or a–z (corresponding to code points
          <code>U+0001</code><em>–</em><code>U+001A</code>). For example,
          <code>/\cM\cJ/</code> matches "\r\n".
        </p>
      </td>
    </tr>
    <tr>
      <td>
        <code>\x<em>hh</em></code>
      </td>
      <td>
        <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_escape"><strong>Hex escape:</strong></a>
        Matches the character with the code <code><em>hh</em></code> (two
        hexadecimal digits).
      </td>
    </tr>
    <tr>
      <td>
        <code>\u<em>HHHH</em></code>
      </td>
      <td>
        <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_escape"><strong>Unicode escape:</strong></a>
        Matches a UTF-16 code-unit with the value
        <code><em>HHHH</em></code> (four hexadecimal digits).
      </td>
    </tr>
    <tr>
      <td>
        <code>\u{<em>H…H</em>}</code>
      </td>
      <td>
        <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Character_escape"><strong>Unicode code point escape:</strong></a>
        (Only when the <code>u</code> flag is set.) Matches the character with
        the Unicode value <code>U+<em>H…H</em></code> (1 to 6 hexadecimal digits).
      </td>
    </tr>
    <tr>
      <td>
        <code>\p{<em>UnicodeProperty</em>}</code>,
        <code>\P{<em>UnicodeProperty</em>}</code>
      </td>
      <td>
        <p>
          <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Unicode_character_class_escape"><strong>Unicode character class escape:</strong></a>
          Matches a character based on its Unicode character properties: for example, emoji characters, or Japanese
          <em>katakana</em> characters, or Chinese/Japanese Han/Kanji characters,
          etc.).
        </p>
      </td>
    </tr>
    <tr>
      <td><code>\</code></td>
      <td>
        <p>
          Indicates that the following character should be treated specially, or
          "escaped". It behaves one of two ways.
        </p>
        <ul>
          <li>
            For characters that are usually treated literally, indicates that
            the next character is special and not to be interpreted literally.
            For example, <code>/b/</code> matches the character "b". By placing
            a backslash in front of "b", that is by using <code>/\b/</code>, the
            character becomes special to mean match a word boundary.
          </li>
          <li>
            For characters that are usually treated specially, indicates that
            the next character is not special and should be interpreted
            literally. For example, "*" is a special character that means 0 or
            more occurrences of the preceding character should be matched; for
            example, <code>/a*/</code> means match 0 or more "a"s. To match
            <code>*</code> literally, precede it with a backslash; for example,
            <code>/a\*/</code> matches "a*".
          </li>
        </ul>
        <div class="notecard note">
          <p>
            <strong>Note:</strong> To match this character literally, escape it
            with itself. In other words to search for <code>\</code> use
            <code>/\\/</code>.
          </p>
        </div>
      </td>
    </tr>
    <tr>
      <td>
        <code><em>x</em>|<em>y</em></code>
      </td>
      <td>
        <p>
          <a href="/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Disjunction"><strong>Disjunction:</strong></a>
          Matches either "x" or "y". Each component, separated by a pipe (<code>|</code>), is called an <em>alternative</em>. For example,
          <code>/green|red/</code> matches "green" in "green apple" and "red" in
          "red apple".
        </p>
        <div class="notecard note">
          <p>
            <strong>Note:</strong> A disjunction is another way to specify "a set of choices", but it's not a character class. Disjunctions are not atoms — you need to use a <a href="/en-US/docs/Web/JavaScript/Guide/Regular_expressions/Groups_and_backreferences">group</a> to make it part of a bigger pattern. <code>[abc]</code> is functionally equivalent to <code>(?:a|b|c)</code>.
          </p>
        </div>
      </td>
    </tr>
  </tbody>
</table>

## Examples

### Looking for a series of digits

In this example, we match a sequence of 4 digits with `\d{4}`. `\b` indicates a [word boundary](/en-US/docs/Web/JavaScript/Guide/Regular_expressions/Assertions) (i.e., do not start or end matching in the middle of a number sequence).

```js
const randomData = "015 354 8787 687351 3512 8735";
const regexpFourDigits = /\b\d{4}\b/g;

console.table(randomData.match(regexpFourDigits));
// ['8787', '3512', '8735']

const aliceExcerpt =
  "I'm sure I'm not Ada,' she said, 'for her hair goes in such long ringlets, and mine doesn't go in ringlets at all.";
const regexpWordStartingWithA = /\b[aA]\w+/g;

console.table(aliceExcerpt.match(regexpWordStartingWithA));
// ['Ada', 'and', 'at', 'all']

const nonEnglishText = "Приключения Алисы в Стране чудес";
const regexpBMPWord = /([\u0000-\u0019\u0021-\uFFFF])+/gu;
// BMP goes through U+0000 to U+FFFF but space is U+0020

console.table(nonEnglishText.match(regexpBMPWord));
["Приключения", "Алисы", "в", "Стране", "чудес"];

const aliceExcerpt =
  "There was a long silence after this, and Alice could only hear whispers now and then.";
const regexpVowels = /[aeiouy]/gi;

console.log("Number of vowels:", aliceExcerpt.match(regexpVowels).length);
// Number of vowels: 26