html运行实例（jsck_element_hasattribute

代码示例：（标识：jsck_element_hasattribute_1）

<!DOCTYPE html>
<html>
<body>
<h1>Element 对象</h1>

<h2>hasAttribute() 方法</h2>

<button id="myBtn" onclick="myFunction()">按钮</button>

<p>按钮是否有 onclick 属性：</p>

<p id="demo"></p>

<script>
const myButton = document.getElementById("myBtn");
let answer = myButton.hasAttribute("onclick");
document.getElementById("demo").innerHTML = answer;
</script>

</body>
</html>