References

edko

Hi everybody,

I am stuck. Anyone willing and able explain, why this code snippet does not do what I am expecting it to do?

Thank you for any hint
Ed

<?php

$TEST="A";

function foo (&$n) {
echo "foo param = $n ";
$n=&$GLOBALS['TEST'];
echo "return \"$n\" ";
}

$x=10;
$m=&$x;
echo "x=$x ";
echo "m=$m ";
foo($m);
echo "x=$x ";
echo "m=$m "; // I expect the char "A". ?

Muntjewerf

I'm not sure what you are trying to achieve here but the output of your function will be an "A" if you run your script. Why use $GLOBALS btw? And & is not needed.
I would write it like this:

$test="A"; 

function foo ($n) { 

global $test;

$n =  $test;
return $n;
} 

$m= 10; 
echo foo($m);

mazzel

edko

Hi mazzle,

exactly that 's what I'm talking about. The script does not print the expected "A" but an unexpected "10".

This is not a real script, so forget the wired GLOBAL stuff. It is just a small test to figure out why this kind of script does not work as expected.

The backround is a recursiv function, that returns references to a specific arrayposition. I want the function to set my parameter to a correct value. Furthermore I need references to identify my arrays. The must not be copied.

With other words: References as "call by reference" function paramters dont work.

swr

When you say $n=&$GLOBALS['TEST']; you are telling $n to stop being a reference to the function's argument and start being a reference to $GLOBALS['TEST'].

To get what you expect, use $n=$GLOBALS['TEST'] instead.