PHP将数组传递给类

Question

I have a array with about 300 indexes and each index has about 8 "sub-indexes"(?). So it is a large(ish) array. I am working on converting my code to oop style and one of my classes(colors) will need this array passed as an argument. So my question is simple....if I create 100 color classes and pass each the array I am not creating 100 separate arrays correct just 100 pointers?

$colors['Apricot'] = array(250,180,160,3341,328,826,194,3332,0);
$colors['Apricot, Light'] = array(255,230,225,3824,8,833,2605,-1,1);

$x=new color();
$y=new color();
$z=new color();

$x->doSomething($colors);
$y->doSomething($colors);
$z->doSomething($colors);

Thee is still only one copy of the array, not three?

Thank you, Todd

Answer 1

True. But in theory the array is copied as value . It's just that PHP-internally it will not be duplicated in memory ... unless one of your objects starts to modify that passed array.

In which case you could pass an explicit & reference rather, or even convert it into an ArrayObject prior. (Again: practically unnecessary if you don't plan on editing the array.)

Answer 2

Yes, you are creating 100 copies, because scalar and array arguments are, by default, passed by value, and not by reference, to class methods in PHP.

In order for the method to take in the argument by reference you'd have to change the method signature by prepending an ampersand to the parameter name, like so:

public function doSomething( &$argument )
{
}

edit:
For a more accurate account of the internal workings, please see mario's answer .