--- title: Element.hasAttribute() slug: Web/API/Element/hasAttribute translation_of: Web/API/Element/hasAttribute --- <div> {{APIRef}}</div> <h2 id="Summary" name="Summary">概述</h2> <p><code>hasAttribute</code> 返回一个布尔值,指示该元素是否包含有指定的属性(attribute)。</p> <h2 id="Syntax" name="Syntax">语法</h2> <pre class="syntaxbox"><var>var result</var> = <var>element</var>.hasAttribute(<var>attName</var>); </pre> <ul> <li><code>result</code> 为返回的布尔值:<code>true</code> 或 <code>false</code>。</li> <li><code>attName</code> 是一个字符串,表示属性的名称。</li> </ul> <h2 id="Example" name="Example">例子</h2> <pre class="brush:js">// 在为属性设置新值前检测该属性是否存在 var d = document.getElementById("div1"); if (d.hasAttribute("align")) { d.setAttribute("align", "center"); }</pre> <h2 id="Notes" name="Notes">备注</h2> <div> {{DOMAttributeMethods}}</div> <h2 id="Specification" name="Specification">规范</h2> <ul> <li><a href="http://www.w3.org/TR/DOM-Level-2-Core/core.html#ID-ElHasAttr">DOM Level 2 Core: hasAttribute</a></li> <li><a href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#ID-ElHasAttr">DOM Level 3 Core: hasAttribute</a></li> </ul>