issue with array reference in php

Question

I am trying to run following code:

$a = array('aa');
function my_func (& $m) {
 return $m;
}
$c = & my_func($a);
$c[] = 'bb';
var_dump($a);
echo '--------';
var_dump($c);

My expectation were that $a and $c would have same reference. But the result is different.

Result i got was:

array(1) { [0]=> string(2) "aa" } --------array(2) { [0]=> string(2) "aa" [1]=> string(2) "bb" } 

What is wrong in above piece of code?

Answer 1

I think what you are looking for is function returning by reference (this in conjunction with passing by reference in your example).

Here is an example:

function &my_func(&$m) {
 return $m;
}
$a = array('aa');
$c = &my_func($a);
$c[] = 'bb';
var_dump($a);
echo "---\n";
var_dump($c);

Outputs:

array(2) {
 [0]=>
 string(2) "aa"
 [1]=>
 string(2) "bb"
}
---
array(2) {
 [0]=>
 string(2) "aa"
 [1]=>
 string(2) "bb"
}

• Ashish: I dint know about returning by reference in php. Thanks. Coming from a non-php background, this is really different for me. And i fear, i dont introduce some unintentional bugs. :(