1 <!doctype html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>Document</title> 6 </head> 7 <body> 8 <div> 9 <ul id="ul"> 10 <li>1</li> 11 <li>2</li> 12 <li>3</li> 13 <li>4</li> 14 <li>5</li> 15 <li>6</li> 16 <li>7</li> 17 <li>8</li> 18 <li>9</li> 19 <li>10</li> 20 </ul> 21 </div> 22 <script> 23 let ul = document.getElementById(‘ul‘); 24 ul.firstElementChild.style.backgroundColor = ‘pink‘; 25 ul.lastElementChild.style.backgroundColor = ‘pink‘; 26 document.write(‘ul子元素个数：‘+ul.children.length) 27 </script> 28 </body> 29 </html>
查找子节点element.firstElementChild,element.lastElementChild,element.children案例
原文：https://www.cnblogs.com/ustc-yy/p/12073236.html