[RESOLVED] Something I've found impossible...

[Scarum]

Hello again, everyone.
This is going to sound very complicated. I have one array, containing a key which is identical to the value of a variable. Let's call the array $x and variable $y. Here's the if statement I have so far:

 if(array_key_exists($y, $x))
{

However, if that statement returns true, I want to assign the value of the array $x where the array's key is $y to a third variable. How would I do that?
Thanks,

Scarum

[Installer]

if (array_key_exists($y, $x)) {
    $x[$y] = $third_variable;
}

[Scarum]

Wow. Thanks for the quick reply.