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diff --git a/files/zh-cn/web/javascript/reference/errors/reserved_identifier/index.html b/files/zh-cn/web/javascript/reference/errors/reserved_identifier/index.html new file mode 100644 index 0000000000..d99acf3fa8 --- /dev/null +++ b/files/zh-cn/web/javascript/reference/errors/reserved_identifier/index.html @@ -0,0 +1,79 @@ +--- +title: 'SyntaxError: "x" is a reserved identifier' +slug: Web/JavaScript/Reference/Errors/Reserved_identifier +tags: + - JavaScript + - 语法错误 + - 错误 +translation_of: Web/JavaScript/Reference/Errors/Reserved_identifier +--- +<div>{{jsSidebar("Errors")}}</div> + +<h2 id="消息提示">消息提示</h2> + +<pre class="syntaxbox">SyntaxError: "x" is a reserved identifier (Firefox) +SyntaxError: Unexpected reserved word (Chrome)</pre> + +<h2 id="错误类型">错误类型</h2> + +<p>{{jsxref("SyntaxError")}}</p> + +<h2 id="哪里出错了?">哪里出错了?</h2> + +<p><a href="/en-US/docs/Web/JavaScript/Reference/Lexical_grammar#Keywords">保留字</a> 用作标记符将会出错. 这些标记符在严格模式和非严格模式下保留:</p> + +<ul> + <li><code>enum</code></li> +</ul> + +<p>以下标记符只会在严格模式下才作为保留字:</p> + +<ul class="threecolumns"> + <li><code>implements</code></li> + <li><code>interface</code></li> + <li>{{jsxref("Statements/let", "let")}}</li> + <li><code>package</code></li> + <li><code>private</code></li> + <li><code>protected</code></li> + <li><code>public</code></li> + <li><code>static</code></li> +</ul> + +<h2 id="示例">示例</h2> + +<h3 id="严格与非严格模式下的保留字">严格与非严格模式下的保留字</h3> + +<p>在两种模式下,<code>enum</code> 标识符都会作为保留字。</p> + +<pre class="brush: js example-bad">var enum = { RED: 0, GREEN: 1, BLUE: 2 }; +// SyntaxError: enum is a reserved identifier +</pre> + +<p>在严格模式下,会有更多的保留字。</p> + +<pre class="brush: js example-bad">"use strict"; +var package = ["potatoes", "rice", "fries"]; +// SyntaxError: package is a reserved identifier +</pre> + +<p>你需要对上述变量重新命名。</p> + +<pre class="brush: js example-good">var colorEnum = { RED: 0, GREEN: 1, BLUE: 2 }; +var list = ["potatoes", "rice", "fries"];</pre> + +<h3 id="升级旧版本浏览器">升级旧版本浏览器</h3> + +<p>假如你还在使用尚未支持 let 或 class 等特性的旧版本浏览器,你应该将它们升级到支持这些新语言特性的版本。</p> + +<pre class="brush: js">"use strict"; +class DocArchiver {} + +// SyntaxError: class is a reserved identifier +//(只会在旧版本浏览器中抛出,例如 Firefox 44 或更老的版本) +</pre> + +<h2 id="相关内容">相关内容</h2> + +<ul> + <li><a href="http://wiki.c2.com/?GoodVariableNames">Good variable names</a></li> +</ul> |
