<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> </head> <body> <input type="text" name="username" id="username" value="" /> <!--<h1></h1>--> <script type="text/javascript"> var inputUser = document.querySelector('#username') // var h1 = document.querySelector('h1') // //输入事件,一般用于检验输入的数据是否符合规范 inputUser.oninput = function(e){ console.log(e) if(e.target.value == 'admin'){ e.target.style.background = 'skyblue' }else{ e.target.style.background = 'pink' } // h1.innerHTML = e.target.value } </script> </body> </html>