I need help

[harmor19]

In the code below I'm simulating data that may be entered by an user.
I am trying to clean the data but it says "First argument to array_keys() should be an array".

PHP Code:

<?php

class Clean
{
    var $p_array;
    
    function cpa()
    {
        foreach ($this->p_array as $this->p_array => $value) 
        {
            $cleaned[array_keys($this->p_array)] .= htmlspecialchars($value);
        }
        return $cleaned;
    }
    
}

$name = "Andrew";
$age = "<b>20</b>";

$input = new Clean;
$input->p_array = array('name' => $name, 'age' => $age);
$input->cpa();

echo $input->$cleaned['name'];

?>