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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/errors/no_variable_name | |
| 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/errors/no_variable_name')
| -rw-r--r-- | files/zh-cn/web/javascript/reference/errors/no_variable_name/index.html | 83 |
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diff --git a/files/zh-cn/web/javascript/reference/errors/no_variable_name/index.html b/files/zh-cn/web/javascript/reference/errors/no_variable_name/index.html new file mode 100644 index 0000000000..4b69a5cec1 --- /dev/null +++ b/files/zh-cn/web/javascript/reference/errors/no_variable_name/index.html @@ -0,0 +1,83 @@ +--- +title: 'SyntaxError: missing variable name' +slug: Web/JavaScript/Reference/Errors/No_variable_name +tags: + - JavaScript + - 语法错误 + - 错误提示 +translation_of: Web/JavaScript/Reference/Errors/No_variable_name +--- +<div>{{jsSidebar("Errors")}}</div> + +<h2 id="错误提示">错误提示</h2> + +<pre class="syntaxbox">SyntaxError: missing variable name (Firefox) +SyntaxError: Unexpected token = (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>缺失变量名。这有很大的可能性是由你的代码中的语法错误造成的。也许是什么地方的逗号出了问题,或者是你正在绞尽脑汁想一个合适的名字。完全可以理解!为变量起名确实让人头疼。</p> + +<h2 id="示例">示例</h2> + +<h3 id="变量名缺失">变量名缺失</h3> + +<pre class="brush: js example-bad">var = "foo"; +</pre> + +<p>为变量起一个合适的明确确实不是一件容易的事情。这种经历每个人都遇到过。</p> + +<pre class="brush: js example-good">var ohGodWhy = "foo";</pre> + +<h3 id="保留字不能作为变量名">保留字不能作为变量名</h3> + +<p>有一些名称是作为<a href="/en-US/docs/Web/JavaScript/Reference/Lexical_grammar#Keywords">保留字</a>而存在的。不好意思,你不能使用!:(</p> + +<pre class="brush: js example-bad">var debugger = "whoop"; +// SyntaxError: missing variable name +</pre> + +<h3 id="一次性声明多个变量">一次性声明多个变量</h3> + +<p>在一次性声明多个变量的时候要特别留意逗号。看看是否有多余的逗号?以及是否不小心把逗号用作了分号?</p> + +<pre class="brush: js example-bad">var x, y = "foo", +var x, = "foo" + +var first = document.getElementById('one'), +var second = document.getElementById('two'), + +// SyntaxError: missing variable name +</pre> + +<p>修复后的代码:</p> + +<pre class="brush: js example-good">var x, y = "foo"; +var x = "foo"; + +var first = document.getElementById('one'); +var second = document.getElementById('two');</pre> + +<h3 id="数组">数组</h3> + +<p>在 JavaScript 中 {{jsxref("Array")}} 字面量需要使用方括号将值包裹起来。下面这样是不对的:</p> + +<pre class="brush: js example-bad">var arr = 1,2,3,4,5; +// SyntaxError: missing variable name +</pre> + +<p>这样写才是正确的:</p> + +<pre class="brush: js example-good">var arr = [1,2,3,4,5];</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> + <li><code><a href="/en-US/docs/Web/JavaScript/Reference/Statements/var">var</a></code></li> + <li><a href="/en-US/docs/Web/JavaScript/Guide/Grammar_and_types#Declarations">Variable declarations in the JavaScript Guide</a></li> +</ul> |
