How to call a function and return data from a function to the global scope?

Question

I created an HTML form that, on submit, opens submit_form.php. Inside, I process the data entered into the form and send a confirmation email. I wrote a function for the mail-sending-process.
Inside the .php file, I have PHP, as well as HTML code. The important parts of the file look like this:

<?php
    $success = "undefined";

    /* ... */

    function send_mail($to, $from, $fromName, $subject, $message) {
        /* headers, etc. */
    
        if (mail($to, $subject, "", $header)) {
            $success = "true";
        } else {
            $success = "false";
        }
    }
?>

<html>
    <body>
        success? <?php echo $success; ?>
    </body
</html>

Now, when loading the HTML on the success site (HTML code below the .php script, in the same file), I put this code to verify whether the email was sent successfully:

success? <?php echo $success; ?>

...which presents the following output: success? undefined

Is the mailto in the same file as the success? <?php echo $success; ?>? — Adder
– Adder, Commented Aug 3, 2017 at 8:51
please share more code, as much as possible. might be a little bit trivial myself here, but make sure the code you wrote is at the top of the page, before the html — Ben Yitzhaki
– Ben Yitzhaki, Commented Aug 3, 2017 at 8:51
Do you get into your send_mail function? try to var_dump something in there, and see if you even access the condition state — Stender
– Stender, Commented Aug 3, 2017 at 9:01
Well, since I receive the email, it probably executes the code, yes. — LinusG.
– LinusG., Commented Aug 3, 2017 at 9:03
Does your function return success variable? afterall if it doesn't return anything it is pointless to have it there. — Atilla Arda Açıkgöz
– Atilla Arda Açıkgöz, Commented Aug 3, 2017 at 9:06

Adder · Accepted Answer · 2017-08-03 09:01:35Z

2

The problem is that the $success variable is not in global scope. Use global to make it global.

function send_mail($to, $from, $fromName, $subject, $message) {
        global $success;

        /* headers, etc. */

        if (mail($to, $subject, "", $header)) {
            $success = "true";
        } else {
            $success = "false";
        }
    }

Variable scope means where the variable is visible. In php,variables local to a function don't live in the global scope by default.

answered Aug 3, 2017 at 9:01

Adder

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5 Comments

LinusG. Over a year ago

Even though I created the variable outside the mail function? It's currently at the very top of the PHP part.

Adder Over a year ago

Yes there is two versions of $success, one in the outer global scope, and one in the functions scope. Thus you need global keyword.

Adder Over a year ago

Where do you call send_mail ? It needs to be executed before the echo $success

LinusG. Over a year ago

Woah! It actually works now. The global keyword was the key(-word, huehue)! Thanks!

mickmackusa Feb 23 at 19:29

The global keyword is not considered best practice because ot potentially floats or interferes with scope variables. Instead, use a return statement.

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