> For the complete documentation index, see [llms.txt](https://ayakaleaf-pro.ayaka.space/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ayakaleaf-pro.ayaka.space/latex/zh-cn/latex-cuo-wu/22-misplaced-noalign.md).

# 位置错误的 \noalign

当你使用了 **`\hline`** 错误地。

## 常见原因

**在表格外使用 \hline：**

该 **`\hline`** 该命令只能在一个 **`tabular`** 环境中使用。你不能将它用于在文档其他地方插入横线，例如在标题页或页眉中。这个错误的一个例子是：

```latex
%In your preamble
\title{On the General Molecular Theory of Heat}
\author{A. Einstein}

% In the body of your document
\maketitle

\hline
```

这将产生下面所示的错误

main.tex，第 5 行

位置不当的 \noalign。

\hline ->\noalign {\ifnum 0=\`}\fi \hrule \\@height \arrayrulewidth \futurelet... l.10 \hline 我只希望在对齐环境的 \cr 之后看到 \noalign。继续吧，我会忽略这种情况。

当你想在 tabular 环境之外添加横线时，你必须使用 **`\hrule`**.

**在表格中错误地使用 \hline：**

使用时 **`\hline`** 在表格中，除第一处外，每一处前都必须加上 **`\\`**。下面展示了此错误的一个例子

```latex
\begin{tabular}{|l|l|} \hline
    First Name: & Albert \\ \hline
    Second Name: & Einstein \hline
\end{tabular}
```

第一个 **`\hline`** 这里的命令是可以的，因为第一处 **`\hline`** 在表格中不需要在前面加上 **`\\`**。问题出在我们最后一个 **`\hline`** 它确实需要在前面加上 **`\\`**。正确的表格写法是：

```latex
\begin{tabular}{|l|l|} \hline
    First Name: & Albert \\ \hline
    Second Name: & Einstein \\ \hline
\end{tabular}
```

![Table.PNG](/files/604163afdf037bf25c73df722dc9333f0c581c8c)


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