きよしろー

<div class="code-block-container"><pre class="language-ts"><code class="language-ts">type IsAllOptional&lt;T&gt; = { [K in keyof T]?: any } extends T ? true : false
</code></pre></div><img src="https://storage.googleapis.com/zenn-user-upload/ed9a000350c0-20230312.png" alt loading="lazy" class="md-img">
<iframe id="zenn-embedded__7932f09ee866b" src="https://embed.zenn.studio/card#zenn-embedded__7932f09ee866b" data-content="https%3A%2F%2Fwww.typescriptlang.org%2Fplay%3FexactOptionalPropertyTypes%3Dfalse%23code%2FC4TwDgpgBAkgzgQQDZIPJmASwPYDsCGSAPACoB8UAvFFAN5QDaA0lJrlANYQjYBmUJALoB%2BAFxR8uEFAC%2BUCAA9gEXABM4AqMKjAATgFdo43oTgQAUOdCQoyNBhwEkVOuZo0w%2BXfgC2cMXSYqqK4%2Bj4ARhC6MgA0bu4Ajoa6IAEAShAAxti6qkRwemwA5jFQ%2BrgcuNgA7rhk5jKWSBDAUHAAFtj6SKokBhDi8HboWHiERMMOY0j1APSzNAB6wpZW4NAActjAk6NOLrTxHl6%2BcOK0QSFhkdFx7lBJUaniGdm5%2BYW4JWUVVbX1jWarQ6XR6ADFTANYIgUCNHOMtjtYVMnHMFlBluYgA" frameborder="0" scrolling="no" loading="lazy"></iframe><a href="https://www.typescriptlang.org/play?exactOptionalPropertyTypes=false#code/C4TwDgpgBAkgzgQQDZIPJmASwPYDsCGSAPACoB8UAvFFAN5QDaA0lJrlANYQjYBmUJALoB+AFxR8uEFAC+UCAA9gEXABM4AqMKjAATgFdo43oTgQAUOdCQoyNBhwEkVOuZo0w+XfgC2cMXSYqqK4+j4ARhC6MgA0bu4Ajoa6IAEAShAAxti6qkRwemwA5jFQ+rgcuNgA7rhk5jKWSBDAUHAAFtj6SKokBhDi8HboWHiERMMOY0j1APSzNAB6wpZW4NAActjAk6NOLrTxHl6+cOK0QSFhkdFx7lBJUaniGdm5+YW4JWUVVbX1jWarQ6XR6ADFTANYIgUCNHOMtjtYVMnHMFlBluYgA" style="display:none" target="_blank" rel="nofollow noopener noreferrer">https://www.typescriptlang.org/play?exactOptionalPropertyTypes=false#code/C4TwDgpgBAkgzgQQDZIPJmASwPYDsCGSAPACoB8UAvFFAN5QDaA0lJrlANYQjYBmUJALoB+AFxR8uEFAC+UCAA9gEXABM4AqMKjAATgFdo43oTgQAUOdCQoyNBhwEkVOuZo0w+XfgC2cMXSYqqK4+j4ARhC6MgA0bu4Ajoa6IAEAShAAxti6qkRwemwA5jFQ+rgcuNgA7rhk5jKWSBDAUHAAFtj6SKokBhDi8HboWHiERMMOY0j1APSzNAB6wpZW4NAActjAk6NOLrTxHl6+cOK0QSFhkdFx7lBJUaniGdm5+YW4JWUVVbX1jWarQ6XR6ADFTANYIgUCNHOMtjtYVMnHMFlBluYgA</a>