<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div class="box">
<textarea name="" id="" cols="30" rows="10"></textarea>
<button>发布</button>
<ul></ul>
</div>
<script>
//1.获取元素
var texts = document.querySelector('textarea');
var btn = document.querySelector('button');
var ul = document.querySelector('ul');
//2.注册时间
btn.onclick = function() {
if (texts.value == "") {
alert('内容不能为空');
return false;
} else {
//(1).创建节点
var lis = document.createElement('li');
//(2).先有li才可以赋值
lis.innerHTML = texts.value;
//(3).清空文本域内容
texts.value = '';
//(4).添加节点
ul.insertBefore(lis, ul.children[0]);
}
}
</script>
</body>
</html>