Revision 846099 of String.prototype.normalize()

<div>{{JSRef}} {{harmony}}</div>

<p>The <strong><code>normalize()</code></strong> method returns the Unicode Normalization Form of a given string (if the value isn't a string, it will be converted to one first).</p>

<h2 id="Syntax">Syntax</h2>

<pre class="syntaxbox">
<code><var>str</var>.normalize([<var>form</var>])</code></pre>

<h3 id="Parameters">Parameters</h3>

<dl>
 <dt><code>form</code></dt>
 <dd>One of <code>"NFC"</code>, <code>"NFD"</code>, <code>"NFKC"</code>, or <code>"NFKD"</code>, specifying the Unicode Normalization Form. If omitted<code>, "NFC"</code> is used.
 <ul>
  <li><code>NFC</code>&nbsp;— Normalization Form Canonical Composition.</li>
  <li><code>NFD</code>&nbsp;— Normalization Form Canonical Decomposition.</li>
  <li><code>NFKC</code>&nbsp;— Normalization Form Compatibility Composition.</li>
  <li><code>NFKD</code>&nbsp;— Normalization Form Compatibility Decomposition.</li>
 </ul>
 </dd>
</dl>

<h3 id="Erros_thrown">Erros thrown</h3>

<dl>
 <dt>{{jsxref("RangeError")}}</dt>
 <dd>A {{jsxref("RangeError")}} is thrown if <code>form</code> isn't one of the values specified above.</dd>
</dl>

<h2 id="Description">Description</h2>

<p>The <code>normalize()</code> method returns the specified Unicode Normalization Form of the string. It does not affect the value of the string itself.</p>

<h2 id="Examples">Examples</h2>

<h3 id="Using_normalize()">Using <code>normalize()</code></h3>

<pre class="brush: js">
// Initial string

// U+1E9B: LATIN SMALL LETTER LONG S WITH DOT ABOVE
// U+0323: COMBINING DOT BELOW
var str = '\u1E9B\u0323';


// Canonically-composed form (NFC)

// U+1E9B: LATIN SMALL LETTER LONG S WITH DOT ABOVE
// U+0323: COMBINING DOT BELOW
str.normalize('NFC'); // '\u1E9B\u0323'
str.normalize();      // same as above


// Canonically-decomposed form (NFD)

// U+017F: LATIN SMALL LETTER LONG S
// U+0323: COMBINING DOT BELOW
// U+0307: COMBINING DOT ABOVE
str.normalize('NFD'); // '\u017F\u0323\u0307'


// Compatibly-composed (NFKC)

// U+1E69: LATIN SMALL LETTER S WITH DOT BELOW AND DOT ABOVE
str.normalize('NFKC'); // '\u1E69'


// Compatibly-decomposed (NFKD)

// U+0073: LATIN SMALL LETTER S
// U+0323: COMBINING DOT BELOW
// U+0307: COMBINING DOT ABOVE
str.normalize('NFKD'); // '\u0073\u0323\u0307'
</pre>

<h2 id="Specifications">Specifications</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('ES6', '#sec-string.prototype.normalize', 'String.prototype.normalize')}}</td>
   <td>{{Spec2('ES6')}}</td>
   <td>Initial definition.</td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Browser compatibility</h2>

<div>{{CompatibilityTable}}</div>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Chrome</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatChrome("34")}}</td>
   <td>{{CompatGeckoDesktop("31")}}</td>
   <td>{{CompatIE("11")}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatNo}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Chrome for Android</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatChrome("34")}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="See_also">See also</h2>

<ul>
 <li><a href="https://www.unicode.org/reports/tr15/">Unicode Standard Annex #15, Unicode Normalization Forms</a></li>
 <li><a href="https://en.wikipedia.org/wiki/Unicode_equivalence">Unicode equivalence</a></li>
</ul>