JS——select标签
<!DOCTYPE html> <html> <head lang="en"> <meta charset="UTF-8"> <title></title> </head> <body> <button id="btn">寻找不同</button> <select id="sel"> <option value="0">香蕉</option> <option value="1">苹果</option> <option value="2">梨子</option> <option value="3">鳄鱼</option> </select> <script> var sel = document.getElementById("sel"); var btn = document.getElementById("btn"); btn.onclick = function () { var opt = sel.getElementsByTagName("option")[3]; opt.selected = true; } </script> </body> </html>