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author | Peter Bengtsson <mail@peterbe.com> | 2020-12-08 14:40:17 -0500 |
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committer | Peter Bengtsson <mail@peterbe.com> | 2020-12-08 14:40:17 -0500 |
commit | 33058f2b292b3a581333bdfb21b8f671898c5060 (patch) | |
tree | 51c3e392513ec574331b2d3f85c394445ea803c6 /files/zh-cn/web/javascript/reference/global_objects/string/touppercase | |
parent | 8b66d724f7caf0157093fb09cfec8fbd0c6ad50a (diff) | |
download | translated-content-33058f2b292b3a581333bdfb21b8f671898c5060.tar.gz translated-content-33058f2b292b3a581333bdfb21b8f671898c5060.tar.bz2 translated-content-33058f2b292b3a581333bdfb21b8f671898c5060.zip |
initial commit
Diffstat (limited to 'files/zh-cn/web/javascript/reference/global_objects/string/touppercase')
-rw-r--r-- | files/zh-cn/web/javascript/reference/global_objects/string/touppercase/index.html | 87 |
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diff --git a/files/zh-cn/web/javascript/reference/global_objects/string/touppercase/index.html b/files/zh-cn/web/javascript/reference/global_objects/string/touppercase/index.html new file mode 100644 index 0000000000..7d0edf43c5 --- /dev/null +++ b/files/zh-cn/web/javascript/reference/global_objects/string/touppercase/index.html @@ -0,0 +1,87 @@ +--- +title: String.prototype.toUpperCase() +slug: Web/JavaScript/Reference/Global_Objects/String/toUpperCase +tags: + - JavaScript + - 原型 + - 字符串 + - 引用 + - 方法 +translation_of: Web/JavaScript/Reference/Global_Objects/String/toUpperCase +--- +<div>{{JSRef}}</div> + +<p><strong><code>toUpperCase()</code></strong> 方法将调用该方法的字符串转为大写形式并返回(如果调用该方法的值不是字符串类型会被强制转换)。</p> + +<div>{{EmbedInteractiveExample("pages/js/string-touppercase.html","shorter")}}</div> + +<p class="hidden">这个交互式示例的源代码存储在GitHub存储库中。如果您想对交互式示例项目作出贡献,请克隆<a href="/zh-CN/docs/">https://github.com/mdn/interactive-examples</a>并向我们发送请求。</p> + +<h2 id="语法">语法</h2> + +<pre class="syntaxbox notranslate"><var>str</var>.toUpperCase()</pre> + +<h3 id="返回值">返回值</h3> + +<p>一个新的字符串,表示转换为大写的调用字符串。</p> + +<h3 id="错误处理">错误处理</h3> + +<dl> + <dt>{{jsxref("TypeError(类型错误)")}}</dt> + <dd>在 {{jsxref("null")}} 或 {{jsxref("undefined")}}类型上调用,例如:<code>String.prototype.toUpperCase.call(undefined)</code>.</dd> +</dl> + +<h2 id="描述">描述</h2> + +<p><code>toUpperCase()</code> 返回转为大写形式的字符串。此方法不会影响原字符串本身的值,因为JavaScript中字符串的值是不可改变的。</p> + +<h2 id="示例">示例</h2> + +<h3 id="基本用法">基本用法</h3> + +<pre class="brush: js notranslate">console.log('alphabet'.toUpperCase()); // 'ALPHABET' +</pre> + +<h3 id="将非字符串类型的_this_(上下文)转为字符串">将非字符串类型的 <code>this</code> (上下文)转为字符串</h3> + +<p>此方法会将任何非字符串类型的值转为字符串, 当你将其上下文 <code>this</code> 值设置为非字符串类型</p> + +<pre class="brush: js notranslate">const a = String.prototype.toUpperCase.call({ + toString: function toString() { + return 'abcdef'; + } +}); + +const b = String.prototype.toUpperCase.call(true); + +// 输出 'ABCDEF TRUE'。 +console.log(a, b); +</pre> + +<h2 id="规范">规范</h2> + +<table class="standard-table"> + <tbody> + <tr> + <th scope="col">规范</th> + </tr> + <tr> + <td>{{SpecName('ESDraft', '#sec-string.prototype.touppercase', 'String.prototype.toUpperCase')}}</td> + </tr> + </tbody> +</table> + +<h2 id="浏览器兼容性">浏览器兼容性</h2> + +<div class="hidden">此页中的兼容性表是从结构化数据生成的。如果你想对数据有所贡献,请查看<a href="/zh-CN/docs/">https://github.com/mdn/browser-compat-data</a>并向我们发送请求。</div> + +<p>{{Compat("javascript.builtins.String.toUpperCase")}}</p> + +<h2 id="参见">参见</h2> + +<ul> + <li>{{jsxref("String.prototype.toLocaleLowerCase()")}}</li> + <li>{{jsxref("String.prototype.toLocaleUpperCase()")}}</li> + <li>{{jsxref("String.prototype.toLowerCase()")}}</li> +</ul> |