自动对焦属性是布尔属性。如果存在，它指定<input>元素应在页面加载时自动获得焦点。下面是一个例子
<!DOCTYPE html> <html> <body> <form action = "/new.php"> First Name: <input type = "text" name = "fname" autofocus><br> Last Name: <input type = "text" name = "lname"><br> <input type="submit"> </form> </body> </html>