anna

<p>真偽値<br>
0だとfalse扱いとなる<br>
<code>??</code>はnullかundefinedの判定なので0でもtrueとなる<br style="display:none">
<span class="embed-block zenn-embedded zenn-embedded-card"><iframe id="zenn-embedded__180767dda167d" src="https://embed.zenn.studio/card#zenn-embedded__180767dda167d" data-content="https%3A%2F%2Fdeveloper.mozilla.org%2Fja%2Fdocs%2FGlossary%2FFalsy" frameborder="0" scrolling="no" loading="lazy"></iframe></span><a href="https://developer.mozilla.org/ja/docs/Glossary/Falsy" style="display:none" target="_blank" rel="nofollow noopener noreferrer">https://developer.mozilla.org/ja/docs/Glossary/Falsy</a><br style="display:none">
<span class="embed-block zenn-embedded zenn-embedded-card"><iframe id="zenn-embedded__61219d8d7cef2" src="https://embed.zenn.studio/card#zenn-embedded__61219d8d7cef2" data-content="https%3A%2F%2Fjust-dooooo-it.com%2Fprogramming%2Fjava-script%2F7%2F" frameborder="0" scrolling="no" loading="lazy"></iframe></span><a href="https://just-dooooo-it.com/programming/java-script/7/" style="display:none" target="_blank" rel="nofollow noopener noreferrer">https://just-dooooo-it.com/programming/java-script/7/</a></p>


<p><code>...</code>　スプレッド構文</p>
<p>配列やオブジェクトの括弧を外してくれる<br style="display:none">
<span class="embed-block zenn-embedded zenn-embedded-card"><iframe id="zenn-embedded__9b686bdd42adb" src="https://embed.zenn.studio/card#zenn-embedded__9b686bdd42adb" data-content="https%3A%2F%2Fproglearn.com%2F2020%2F04%2F11%2F%25E3%2580%2590javascript%25E3%2580%2591-%25E3%2583%2589%25E3%2583%2583%25E3%2583%2588%25E3%2581%258C3%25E3%2581%25A4-%25EF%25BC%259F%25E3%2581%2593%25E3%2582%258C%25E3%2580%2581%25E3%2581%25A9%25E3%2581%2586%25E3%2582%2584%25E3%2581%25A3%25E3%2581%25A6%25E4%25BD%25BF%25E3%2581%2586%25E3%2581%25AE%2F" frameborder="0" scrolling="no" loading="lazy"></iframe></span><a href="https://proglearn.com/2020/04/11/%E3%80%90javascript%E3%80%91-%E3%83%89%E3%83%83%E3%83%88%E3%81%8C3%E3%81%A4-%EF%BC%9F%E3%81%93%E3%82%8C%E3%80%81%E3%81%A9%E3%81%86%E3%82%84%E3%81%A3%E3%81%A6%E4%BD%BF%E3%81%86%E3%81%AE/" style="display:none" target="_blank" rel="nofollow noopener noreferrer">https://proglearn.com/2020/04/11/【javascript】-ドットが3つ-？これ、どうやって使うの/</a></p>
