无法从$ _POST设置变量

Question

I can't set a variable from a post array.

I have a simple form with a hidden field in it: <input name="sid" type="hidden" id="sid" value="<?=$sid?>">

This hidden field gets sent off to a second file (exec.php) where I have the following code:

$sid = $_POST['sid'];

For some reason, when trying to set $sid, it gets a NULL value. For haha's, I ran the following:

foreach($_POST as $var => $value)
{
echo $var . ' : ' . $value . "<br>";
}

This provided a correct value of 1938 for sid. I've looked at this for 3 hours and can't find what is happening. I expect something extremely stupid...any thoughts?

---

Here is the form on enter.php

    <form name="form1" method="post" action="exec.php">
     <input name="sid" type="hidden" id="sid" value="<? echo($sid); ?>">
     <input name="ticket_totals" type="hidden" id="ticket_totals" value="<?=$ticket_totals?>">
     <input name="emp" type="hidden" id="emp" value="<?=$emp?>">
     <input name="submit" type="submit" id="submit" value="Submit">
     <input type="submit" name="submit" id="submit" value="Close">
    </form>

Here is the POST output on exec.php: type : Other ticket_totals : 0 emp : 105 sid : 1939 submit : Submit

---

Okay - this was poor syntax on my part but now I'm curious as to why.

I left out quotation marks - the solution is as simple as this: $sid = $_POST["sid"]

Now it works like a champ.

Any takers on why? I'd guess there is a setting in the php.ini that requires the quotes. Strangely enough, I have other variables called from the POST array that i'm not using quotes for and they're working fine...

Answer 1

Use Console in FireBug to inspect the POST request to see what is the sid value that is being sent.

If the sid value in request is ok, use var_dump($_POST["sid"]); to see the results on the server.

EDIT: it's considered good PHP style to use the quotes when accessing the associative array because quote-less keys are indistinguishable from constants:

define('myVar',3);
echo $array[myVar]; // retrieves $array[3], not $array['myVar'];