use implode in $_GET - php

Question

I have some forms in my page like :
<form method="get">
Enter Your Firstname :<input type="text" name="t1" />
Enter Your Lastname :<input type="text" name="t2" />
<input type="submit" name="sb" />
</form>
so users will fill this form and i want to have values of this form separated with comma
for example
John,Smith
James,Baker
so here is my php code
if ( isset ($_GET['sb']))
{
$t_array = array("t1","t2");
foreach ( $t_array as $key )
{
echo implode(',' , $_GET[$key]);
}
}
When i try to do this , i got this error :
Warning: implode() [<a href='function.implode'>function.implode</a>]: Invalid arguments passed in PATH on line 24
i don't know why i can't use implode in $_GET or $_POST
so how can i solve this problem ?
P.S : i want to use array and implode in my page , please don't write about other ways

Answer 1

There is an error in your logic.
here is sample code that might help you:
$t_array = array($_GET['t1'], $_GET['t2']);
$imploded = implode(',', $t_array);
echo $imploded;
This will work.

Answer 2

You're calling implode on a value, not an array. This code
echo implode(',' , $_GET[$key]);
calls it on $_GET[$key], which is a string.
You are trying for implode($_GET);.

Answer 3

What you need is something like below, you don't actually need implode for this:
if ( isset ($_GET['sb']))
{
$t_array = array("t1","t2");
$result = '';
foreach ( $t_array as $key )
{
if ($result != '') $result .= ',';
$result .= $_GET[$key];
}
}

Answer 4

You can't impode strings...
Try something like this:
if ( isset ($_GET['sb']))
{
$t_array = array("t1","t2");
$arr = array();
foreach ( $t_array as $key )
{
$arr[] = $_GET[$key];
}
echo implode(',' , $arr);
}