添加到动态变量变量数组

Question

In my class, I have a public variable:

public $full_rows = array("text");

I want to be able to add to that array, like so:

$form->addarray("full_rows", array("url","name"));

So I have this function:

public function addarray($arrayname, $array = array()) {
    array_merge($this->$arrayname, $array);     
}

Except it's not affecting the array full_rows at all. Why not?

Edit Thanks to roullie for the correct answer. Turns out I'd forgotten that array_merge returns the merged array rather than just doing it. I thought it was a problem with variable variables (as I'd never used them before).

Here is my final function:

public function addarray($arrayname, $array = array()) {
    if((isset($this->$arrayname)) && (is_array($array))) {
        $this->{$arrayname} = array_merge($this->{$arrayname}, $array);
    } else {
        return false;   
    }
}

Answer 1

set the value of the merged array to your $full_rows

public function addarray($arrayname, $array = array()) {
    $this->$arrayname = array_merge($this->$arrayname, $array);     
}