可下载图片
<html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> </head> <body> <input type="text" value="手机"> <script> var text = document.querySelector('input'); text.onfocus = function(){ if(this.value=="手机"){ this.value=""; } } text.onblur = function(){ if(this.value==""){ this.value="手机"; } } </script> </body> <html>