It should be noted that the returned methods are dependant on the current scope. See this example:

<?php
class C
{
    private function privateMethod()
    {
        
    }
    public function publicMethod()
    {
        
    }
    public function __construct()
    {
        echo '$this:';
        var_dump(get_class_methods($this));
        echo 'C (inside class):';
        var_dump(get_class_methods('C'));
    }
}
$c = new C;
echo '$c:';
var_dump(get_class_methods($c));
echo 'C (outside class):';
var_dump(get_class_methods('C'));
?>

Output:

$this:
array
  0 => string 'privateMethod' (length=13)
  1 => string 'publicMethod' (length=12)
  2 => string '__construct' (length=11)

C (inside class):
array
  0 => string 'privateMethod' (length=13)
  1 => string 'publicMethod' (length=12)
  2 => string '__construct' (length=11)

$c:
array
  0 => string 'publicMethod' (length=12)
  1 => string '__construct' (length=11)

C (outside class):
array
  0 => string 'publicMethod' (length=12)
  1 => string '__construct' (length=11)