---
title: 減算 (-)
slug: Web/JavaScript/Reference/Operators/Subtraction
tags:
  - JavaScript
  - Language feature
  - Operator
  - Reference
translation_of: Web/JavaScript/Reference/Operators/Subtraction
---
<div>{{jsSidebar("Operators")}}</div>

<p>減算演算子 (<code>-</code>) は2つのオペランドを減算し、それらの差を生成します。</p>

<div>{{EmbedInteractiveExample("pages/js/expressions-subtraction.html")}}</div>

<div></div>



<h2 id="構文">構文</h2>

<pre class="syntaxbox notranslate"><strong>Operator:</strong> <var>x</var> - <var>y</var>
</pre>

<h2 id="例">例</h2>

<h3 id="数値による減算">数値による減算</h3>

<pre class="brush: js notranslate">5 - 3     // 2
3 - 5     // -2</pre>

<h3 id="非数による減算">非数による減算</h3>

<pre class="brush: js notranslate">'foo' - 3 // NaN</pre>

<h2 id="仕様">仕様</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">仕様</th>
  </tr>
  <tr>
   <td>{{SpecName('ESDraft', '#sec-subtraction-operator-minus', 'Subtraction operator')}}</td>
  </tr>
 </tbody>
</table>

<h2 id="ブラウザーの互換性">ブラウザーの互換性</h2>



<p>{{Compat("javascript.operators.subtraction")}}</p>

<h2 id="関連項目">関連項目</h2>

<ul>
 <li><a href="https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/Addition">加算演算子</a></li>
 <li><a href="https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/Multiplication">乗算演算子</a></li>
 <li><a href="https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/Division">除算演算子</a></li>
 <li><a href="https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/Remainder">剰余演算子</a></li>
 <li><a href="https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/Exponentiation">べき乗演算子</a></li>
 <li><a href="https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/Increment">インクリメント演算子</a></li>
 <li><a href="https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/Decrement">デクリメント演算子</a></li>
 <li><a href="https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/Unary_negation">単項マイナス演算子</a></li>
 <li><a href="https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/Unary_plus">単項プラス演算子</a></li>
</ul>