php copying array elements by value, not by reference

You can take advantage of the fact that PHP will dereference the results of a function call.

Here's some example code I whipped up:

$x = 'x';$y = 'y';$arr = array(&$x,&$y);print_r($arr);echo "<br/>";$arr2 = $arr;$arr2[0] = 'zzz';print_r($arr);print_r($arr2);echo "<br/>";$arr2 = array_flip(array_flip($arr));$arr2[0] = '123';print_r($arr);print_r($arr2);

The results look like this:

Array ( [0] => x [1] => y )Array ( [0] => zzz [1] => y ) Array ( [0] => zzz [1] => y )Array ( [0] => zzz [1] => y ) Array ( [0] => 123 [1] => y ) 

You can see that the results of using array_flip() during the assigment of $arr to $arr2 results in differences in the subsequent changes to $arr2, as the array_flip() calls forces a dereference.

It doesn't seem terribly efficient, but it might work for you if $this->x->getResults() is returning an array:

$data['x'] = array_flip(array_flip($this->x->getResults()));$data['y'] = $data['x'];

See this (unanswered) thread for another example.

If everything in your returned array is an object however, then the only way to copy an object is to use clone(), and you would have to iterate through $data['x'] and clone each element into $data['y'].

Example:

$data['x'] = $this->x->getResults();$data['y'] = array();foreach($data['x'] as $key => $obj) {    $data['y'][$key] = clone $obj;}

array_flip() won't work when array values are not strings nor integers.I found a simple solution, however:

$clonedArr = (array)clone(object)$arr;

This works thanks to the properties of clone on an object.

Not simple. Read about clone

BUT! if your elements are not objects and not refence type variables you have no problem.

Example for reference types:

$v=11;$arr[]=&$v;