blog/content/post/2009/08/10/2009-08-10-00001214.md

---
title: ref関数 – 何のリファレンスなのかを判断する
author: kazu634
date: 2009-08-10
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categories:
  - Perl

---
<div class="section">
<p>
    リファレンスをでリファレンスしたものが、
</p>
  
<ul>
<li>
      スカラー変数
</li>
<li>
      配列
</li>
<li>
      ハッシュ
</li>
</ul>
  
<p>
    なのかを判断する関数がrefです。
</p>
  
<h4>
    使い方
</h4>
  
<pre class="syntax-highlight">
<span class="synStatement">use strict</span>;
<span class="synStatement">use warnings</span>;
<span class="synStatement">use </span>Perl6::Say;
<span class="synStatement">use utf8</span>;
<span class="synStatement">my</span> <span class="synIdentifier">$foo</span> = <span class="synConstant">10</span>;
<span class="synStatement">my</span> <span class="synIdentifier">@array</span> = ( <span class="synConstant">1</span>, <span class="synConstant">2</span>, <span class="synConstant">3</span>, <span class="synConstant">4</span>, <span class="synConstant">5</span> );
<span class="synStatement">my</span> <span class="synIdentifier">$ref_foo</span>   = <span class="synIdentifier">\$foo</span>;
<span class="synStatement">my</span> <span class="synIdentifier">$ref_array</span> = <span class="synIdentifier">\@array</span>;
<span class="synStatement">my</span> <span class="synIdentifier">$ref_hash</span>  = {
<span class="synConstant">&#34;key&#34;</span> =&#62; <span class="synConstant">13</span>,
<span class="synConstant">&#34;foo&#34;</span> =&#62; <span class="synConstant">15</span>,
};
say <span class="synStatement">ref</span>(<span class="synIdentifier">$ref_foo</span>);
say <span class="synStatement">ref</span>(<span class="synIdentifier">$ref_array</span>);
say <span class="synStatement">ref</span>(<span class="synIdentifier">$ref_hash</span>);
</pre>
  
<h4>
    実行例
</h4>
  
<pre class="syntax-highlight">
~/working/tmp_perl on simoom634 <span class="synStatement">[</span><span class="synConstant">506</span><span class="synStatement">]</span> $: perl <span class="synStatement">test</span>.pl
SCALAR
ARRAY
HASH
</pre>
</div>