HTML required 属性</strong>是一个布尔属性，用于指定<em>在提交表单之前必须填写 <textarea> 元素</em>。</p> <p><strong>句法：</strong> </p> <div class="hcb_wrap"> <pre class="prism line-numbers lang-html" data-lang="HTML"><code class="replace"><textarea required> </code></pre> </div> <p><strong>示例：</strong>此示例说明了 Textarea 元素中 required 属性的使用。 </p> <div class="hcb_wrap"> <pre class="prism line-numbers lang-html" data-lang="HTML"><code class="replace"><!DOCTYPE html> <html> <head> <title>required Attribute</title> <style> h1, h2 { color: green; font-style: italic; } body { text-align: center; } </style> </head> <body> <h1>GeeksForGeeks</h1> <h2>HTML Textarea required attribute </h2> <form action="#"> <textarea rows="7" cols="50" name="comment" required>