为什么我收到一条错误，指出“mail（）期望参数1是字符串”？

Question

So basically, I am trying to create a bulk email application.

I am allowing the upload of a CSV file with a few emails, and once I click send they will all be processed and sent.

I parse the CSV file into an array, and I am using a foreach loop to handle each email address and send it.

For example, this is called after the csv array has been populated:

foreach($csv as $email_address)
{
   $sendHeaders = "headers here";
   $sendSubject = "subject here";
   $sendText = "long email text here";

   mail($email_address,$sendSubject,$sendText,$sendHeaders);
}

Although, I seem to get the error of:

Warning: mail() expects parameter 1 to be string

It states that the error is on line 54, which is the line where my mail() function is being called.

Does anyone have any idea to why this is happening?

---

EDIT:

Here is a var_dump of my array if anyone is after it:

Array
(
    [0] => Array
        (
            [0] => email1@foo.com
            [1] => email2@foo.com
            [2] => email3@foo.com
        )

)

Answer 1

Change your loop to:

foreach($csv as $email_addresses) {
    foreach($email_addresses as $email_address) {
        $sendHeaders = "headers here";
        $sendSubject = "subject here";
        $sendText = "long email text here";

        mail($email_address,$sendSubject,$sendText,$sendHeaders);
    }
}

In fact the problem was that your $csv is a two-level array, hence its elements are not strings, you must iterate on its elements to get the actual email addresses.

Also, if $sendHeaders and/or $sendSubject are always the same, you could move them before the loop so you do not set them each time.

Lastly, as @Dagon suggested, if $csv always has only one element, you could simply do:

foreach($csv[0] as $email_address) {
    $sendHeaders = "headers here";
    $sendSubject = "subject here";
    $sendText = "long email text here";

    mail($email_address,$sendSubject,$sendText,$sendHeaders);
}