javascript下拉框不被选中大类的区别方法 时间:2020-05-12 人气:0 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>runcode</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="Author" content="Sheneyan" /> </head> <body> <select> <optgroup label="a"> <option>a1</option> <option>a2</option> <option>a3</option> </optgroup> <optgroup label="b"> <option>b1</option> <option>b2</option> <option>b3</option> </optgroup> </select> </body> </html> [Ctrl+A 全选 注:如需引入外部Js需刷新才能执行] 加载全部内容