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---
title: Unicode property escapes
slug: Web/JavaScript/Guide/Regular_Expressions/Unicode_Property_Escapes
translation_of: Web/JavaScript/Guide/Regular_Expressions/Unicode_Property_Escapes
---
<p>{{jsSidebar("JavaScript Guide")}}</p>
<p><strong>Unicode property escapes</strong> <a href="https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Guide/Regular_Expressions">正则表达式</a> 支持根据 Unicode 属性进行匹配，例如我们可以用它来匹配出表情、标点符号、字母(甚至适用特定语言或文字)等。同一符号可以拥有多种 Unicode 属性，属性则有 binary ("boolean-like") 和 non-binary 之分。</p>
<div>{{EmbedInteractiveExample("pages/js/regexp-unicode-property-escapes.html", "taller")}}</div>
<div class="note">
<p><strong>备注：</strong>使用 Unicode 属性转义依靠 <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/unicode"><code>\u</code> 标识</a>，<code>\u</code> 表示该字符串被视为一串 Unicode 代码点。参考 <code><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/unicode">RegExp.prototype.nicode</a></code>.</p>
</div>
<div class="note">
<p><strong>备注：</strong> 某些 Unicode 属性比<a href="/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Character_Classes">字符类</a>(如 <code>\w</code> 只匹配拉丁字母 <code>a</code> 到 <code>z</code>)包含更多的字符 ，但后者浏览器兼容性更好 (截至2020 一月).</p>
</div>
<h2 id="句法">句法</h2>
<pre class="brush: js">// Non-binary 属性
\p{<em>Unicode属性值</em>}
\p{<em>Unicode属性名</em>=<em>Unicode属性值</em>}
// Binary and non-binary 属性
\p{<em>UnicodeBinary属性名</em>}
// \P 为 \p 取反
\P{<em>Unicode属性值</em>}
\P{<em>UnicodeBinary属性名</em>}
</pre>
<ul>
<li><a href="https://unicode.org/reports/tr18/#General_Category_Property">General_Category</a> (<code>gc</code>)</li>
<li><a href="https://unicode.org/reports/tr24/#Script">Script</a> (<code>sc</code>)</li>
<li><a href="https://unicode.org/reports/tr24/#Script_Extensions">Script_Extensions</a> (<code>scx</code>)</li>
</ul>
<p>参考 <a href="https://www.unicode.org/Public/UCD/latest/ucd/PropertyValueAliases.txt">PropertyValueAliases.txt </a></p>
<dl>
<dt>UnicodeBinary属性名</dt>
<dd><a href="https://tc39.es/ecma262/#table-binary-unicode-properties">Binary 属性</a>名. E.g.: <code><a href="https://unicode.org/reports/tr18/#General_Category_Property">ASCII</a></code>. <code><a href="https://unicode.org/reports/tr44/#Alphabetic">Alpha</a></code>, <code>Math</code>, <code><a href="https://unicode.org/reports/tr44/#Diacritic">Diacritic</a></code>, <code><a href="https://unicode.org/reports/tr51/#Emoji_Properties">Emoji</a></code>, <code><a href="https://unicode.org/reports/tr44/#Hex_Digit">Hex_Digit</a></code>, <code>Math</code>, <code><a href="https://unicode.org/reports/tr44/#White_Space">White_space</a></code>, 等. 另见 <a href="https://www.unicode.org/Public/UCD/latest/ucd/PropList.txt">Unicode Data PropList.txt</a>.</dd>
<dt>Unicode属性名</dt>
<dd><a href="https://tc39.es/ecma262/#table-nonbinary-unicode-properties">Non-binary</a> 属性名:</dd>
<dt>Unicode属性值</dt>
<dd>很多值有同名或简写(e.g. 对应着 <code>General_Category</code> 属性名的属性值 <code>Decimal_Number</code> 可以写作 <code>Nd</code>, <code>digit</code>, 或 <code>Decimal_Number</code>). 大多数属性值的 <em><code>Unicode属性名</code></em> 和等号可以省去。如果想明确某 <em><code>Unicode属性名</code></em>，必须给出它的值。</dd>
</dl>
<div class="note">
<p><strong>备注：</strong> 因为可使用的属性和值太多，这里不一一赘述，仅提供几个例子。</p>
</div>
<h2 id="基本原理">基本原理</h2>
<p>在 ES2018 之前，JavaScript 没有强有效的方式用匹配出不同<code>文字</code>(如马其顿语，希腊语，Georgian 等)或不同 <code>属性名</code> (如 Emoji 等)的字符。另见 <a href="https://github.com/tc39/proposal-regexp-unicode-property-escapes">tc39 Proposal on Unicode Property Escapes</a>.</p>
<h2 id="例子">例子</h2>
<h3 id="（一般类别）General_categories">（一般类别）General categories</h3>
<p>General categories 对 Unicode 字符进行分类，子类别用于精确定义类别。长名和简写的 Unicode 属性转义都可用.</p>
<p>它们可匹配字母、数字、符号、标点符号、空格等等。一般类别详见 <a href="https://unicode.org/reports/tr18/#General_Category_Property">the Unicode specification</a>.</p>
<pre class="brush: js">// finding all the letters of a text
let story = "It’s the Cheshire Cat: now I shall have somebody to talk to.";
// Most explicit form
story.match(/\p{General_Category=Letter}/gu);
// It is not mandatory to use the property name for General categories
story.match(/\p{Letter}/gu);
// This is equivalent (short alias):
story.match(/\p{L}/gu);
// This is also equivalent (conjunction of all the subcategories using short aliases)
story.match(/\p{Lu}|\p{Ll}|\p{Lt}|\p{Lm}|\p{Lo}/gu);
</pre>
<h3 id="文字（Script）和文字扩充（Script_Extensions）">文字（Script）和文字扩充（Script_Extensions）</h3>
<p>某些语言使用不同的文字，如英语和西班牙语使用拉丁文，而阿拉伯语和俄语用阿拉伯文和俄文。<code>Script</code> 和 <code>Script_Extensions</code> Unicode 属性允许正则表达式根据字符所属的<code>文字</code>或该文字所属的<code>文字扩充</code>进行匹配。</p>
<p>比如，<code>A</code> 属于 <code>拉丁文</code>，<code>ε</code> 属于<code>希腊(Greek)</code>文。</p>
<pre class="brush: js">let mixedCharacters = "aεЛ";
// Using the canonical "long" name of the script
mixedCharacters.match(/\p{Script=Latin}/u); // a
// Using a short alias for the script
mixedCharacters.match(/\p{Script=Grek}/u); // ε
// Using the short name Sc for the Script property
mixedCharacters.match(/\p{Sc=Cyrillic}/u); // Л
</pre>
<p>详见 <a href="https://unicode.org/reports/tr24/#Script">the Unicode specification</a> 和 <a href="https://tc39.es/ecma262/#table-unicode-script-values">Scripts table in the ECMAScript specification</a>.</p>
<p>某字符用于多种文字时，<code>Script</code> 优先匹配最主要使用那个字符的文字。如果想要根据非主要的文字进行匹配，我们可以使用 <code>Script_Extensions</code> 属性 (简写为<code>Scx</code>).</p>
<pre class="brush: js">// ٢ is the digit 2 in Arabic-Indic notation
// while it is predominantly written within the Arabic script
// it can also be written in the Thaana script
"٢".match(/\p{Script=Thaana}/u);
// null as Thaana is not the predominant script super()
"٢".match(/\p{Script_Extensions=Thaana}/u);
// ["٢", index: 0, input: "٢", groups: undefined]
</pre>
<h3 id="Unicode_属性转义_vs._字符类">Unicode 属性转义 vs. 字符类</h3>
<p>JavaScript 正则表达式可以使用 <a href="/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Character_Classes">字符类</a> 尤其是 <code>\w</code> 或 <code>\d</code> 匹配字母或数字，然而，这样的形式只匹配拉丁文字的字符 (换言之，<code>a</code> 到 <code>z</code>、 <code>A</code> 到 <code>Z</code> 的 <code>\w</code> 和 <code>0</code> 到 <code>9</code> 的 <code>\d</code>)，见<a href="/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Character_Classes#Looking_for_a_word_from_Unicode_characters">例子</a>，这样的使用放到非拉丁文本中是有些蠢的。</p>
<p>Unicode 属性转义 categories 包含更多字符， <code>\p{Letter}</code> 或 <code>\p{Number}</code> 将会适用于任何文字。</p>
<pre class="brush: js">// Trying to use ranges to avoid \w limitations:
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));
// Using Unicode property escapes instead
const regexpUPE = /\p{L}+/gu;
console.table(nonEnglishText.match(regexpUPE));
</pre>
<h2 id="Specifications">Specifications</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">Specification</th>
</tr>
<tr>
<td>{{SpecName('ESDraft', '#sec-runtime-semantics-unicodematchproperty-p', 'RegExp: Unicode property escapes')}}</td>
</tr>
</tbody>
</table>
<h2 id="Browser_compatibility">Browser compatibility</h2>
<p>For browser compatibility information, check out the <a href="/en-US/docs/Web/JavaScript/Guide/Regular_Expressions#Browser_compatibility">main Regular Expressions compatibility table</a>.</p>
<h2 id="See_also">See also</h2>
<ul>
<li><a href="/en-US/docs/Web/JavaScript/Guide/Regular_Expressions">Regular expressions guide</a>
<ul>
<li><a href="/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Character_Classes">Character classes</a></li>
<li><a href="/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Assertions">Assertions</a></li>
<li><a href="/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Quantifiers">Quantifiers</a></li>
<li><a href="/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Groups_and_Ranges">Groups and ranges</a></li>
</ul>
</li>
<li><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp">The <code>RegExp()</code> constructor</a></li>
<li><code><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/unicode">RegExp.prototype.unicode</a></code></li>
<li><a href="https://en.wikipedia.org/wiki/Unicode_character_property">Unicode character property — Wikipedia</a></li>
<li><a href="https://2ality.com/2017/07/regexp-unicode-property-escapes.html">A blog post from Axel Rauschmayer about Unicode property escapes</a></li>
<li><a href="https://unicode.org/reports/tr18/#Categories">The Unicode document for Unicode properties</a></li>
</ul>
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