监听按钮的点击来隐藏元素，结果显示：Cannot read properties of null (reading 'hidden')，什么原因？

发布于
2023-07-19 贵州

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<button class = "btn">点击隐藏</button>

<div clsss = "box" style = "color:red">我是盒子</div>
<script>

//拿到boxEl元素
var boxEl = document.querySelector(".box");
//获取按钮元素
var btnEl = document.querySelector(".btn");
//监听按钮的点击
btnEl.onclick = function() {
  console.log(boxEl.hidden);
}

</script>
</body>
</html>