新增节点代码格式先创建一个节点,后放入指定元素 创建节点123456<script> const div = document.createElement('div') div.innerHTML = '豆棍杜子' div.style.fontSize = '20px' console.log(div)</script> 放入指定元素,appendChild()方法12345678910<span></span><script> const div = document.createElement('div') div.innerHTML = '豆棍杜子' div.style.fontSize = '20px' console.log(div) const span = document.querySelector('span') span.appendChild(div)</script> 放在某个指定元素前面,insertBefore()方法1234const h1 = document.createElement('h1')h1.innerHTML = 'Good morning!'h1.style.backgroundColor = "blue"span.insertBefore(h1,div)