[RESOLVED] How to get $_POST values

richie

When a form is posted,
one can get values using the global $_POST array like this:

$first_name = $POST["first_name"];
$last_name = $POST["last_name"];

But what happens when the field name in the form is dynamic? Something like this:

$field_prefix = array("first", "last");

foreach($field_prefix as $value) {

$field_name = "{$value}name";
echo $POST["$field_name"];
}

Why is the array loop not printing out anything?

NogDog

Works OK for me:

<pre><?php
$_POST['first_name'] = "First";
$_POST['last_name'] = "Last";
$first_name = $_POST["first_name"];
$last_name = $_POST["last_name"];
echo "$first_name\n$last_name\n";
$field_prefix = array(
   "first",
   "last"
);
foreach($field_prefix as $value) {
   $field_name = "{$value}_name";
   echo $_POST["$field_name"]."\n";
}
?></pre>

Output:

First
Last
First
Last

richie

NogDog;10955939 wrote:

Works OK for me:

<pre><?php
$_POST['first_name'] = "First";
$_POST['last_name'] = "Last";
$first_name = $_POST["first_name"];
$last_name = $_POST["last_name"];
echo "$first_name\n$last_name\n";
$field_prefix = array(
   "first",
   "last"
);
foreach($field_prefix as $value) {
   $field_name = "{$value}_name";
   echo $_POST["$field_name"]."\n";
}
?></pre>

Output:

OK. I found the problem.

If $value contains a period/dot, it won't work.
I replaced the period with underscore, and it worked.

I'm not sure why a dot is a problem, but it is.

Thanks for trying it out.

bradgrafelman

richie wrote:
I'm not sure why a dot is a problem, but it is.

From the PHP manual (reference: [man]variables.external[/man]):

PHP Manual wrote:
Dots in incoming variable names

Typically, PHP does not alter the names of variables when they are passed into a script. However, it should be noted that the dot (period, full stop) is not a valid character in a PHP variable name.

...

For this reason, it is important to note that PHP will automatically replace any dots in incoming variable names with underscores.

richie

You learn something new everyday.

Thanks for digging up that answer.