过滤从电子邮件消息（经由表格生成）零值

Question

/*user is filing up form values that includes name , phone , product quantity...etc */<BR/> 
/*After clicking button */ 
$mailto = randomuseremail@xxx.com 
/* *// 
$value1=$_GET['value1']; 
$value2=$_GET['value2']; 
$value3=$_GET['value3']; 
. 
. 
. 
$value20=$_GET['value20']; 

$message = <<< EOD 
< br> value 1 is: $value1; 
< br> value 2 is: $value2; 
< br> value 3 is: $value3; 
. 
. 
. 
< br> value 20 is - $value20; 
... EOD ; 
$success = mail($mailto, $message , $body, $headers); 

用户收到该电子邮件

You orderd: 
value 1 is: 1 
value 2 is: 0 
value 3 is: 0 
... 
value 20 is: 0 

代替显示该如何筛选/不显示0或“”值whitin EOD（或有更好法） 这是所需的电子邮件输出：

You orderd: 
value 1 is: 1 /*or any other non zero | "" value */ 

Answer 1

$message = ''; 
for ($i = 1; $i <= 20; $i++) { 
    if ($_GET['value'.$i] != 0) { 
    $message .= "<br> value $i is: " . $_GET['value'.$i] 
    } 
}