1. document.querySlector()
2.document.querySlectorAll()
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>新增选择器</title> <script type="text/javascript"> window.onload = function(){ var oDiv = document.querySelector('#div1'); alert(oDiv); var aLi = document.querySelectorAll('.list li'); alert(aLi.length) } </script> </head> <body> <div id="div1"> <ul class="list"> <li>1</li> <li>2</li> <li>3</li> <li>4</li> <li>5</li> <li>6</li> </ul> </div> </body> </html>