Passing an array copy to a function expecting a reference - php

Question

I have a loop of the following kind:
foreach ($values as $key => $value) {
$attrs = array('NAME' => $key);
myproc ($attrs);
......
}
Where in myproc the first parameter is defined by reference:
function myproc (& attrs) { .... }
myproc adds the passed value to some structure.
The trouble with this is that at loop end, all the arrays added to the generated structure contains the same value, the last value extracted from the loop.
I tried also something like this :
foreach ($values as $key => $value) {
$attrs = array('NAME' => $key);
$copy = $attrs;
myproc ($copy);
......
}
but the result is the same. I'not allowed to modify the procedure. Any suggestions?

Answer 1

Based on the comment below your question, it seems that the problem is that you are passing a reference and this reference gets updated in the loop, leading to updates in the object you are generating in your function.
To avoid this, you need to unset the variable after the function call so that the link between the value in your object and the referenced variable is broken:
foreach ($values as $key => $value) {
$attrs = array('NAME' => $key);
myproc ($attrs);
// unset the variable so that newer values of it will have no effect
// on the object generated in `myproc`
unset($attrs);
......
}
Also see the manual.

Answer 2

<?php
foreach(['red','pink','green'] as $colour) {
$attrs = ['colour' => $colour];
if(colourToAction($attrs)) {
$results[] = $attrs;
}
}
var_export($results);
function colourToAction(&$attrs) {
$actions = ['red'=>'stop','amber'=>'wait', 'green' => 'go'];
if(isset($attrs['colour']) && isset($actions[$attrs['colour']])){
$attrs['action'] = $actions[$attrs['colour']];
return true;
}
}
Output:
array (
0 =>
array (
'colour' => 'red',
'action' => 'stop',
),
1 =>
array (
'colour' => 'green',
'action' => 'go',
),
)