pass by ref

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pass by ref

January 12, 2013, 01:38:31 pm

emanuele is now completely confused...

function foo(&$var)
{
    $var++;
}

$a=5;
foo($a);

works.

Code: [Select]

function foo(&$var)
{
    $var++;
}

$a=5;
call_user_func_array('foo', array($a));

QuoteWarning: Parameter 1 to foo() expected to be a reference, value given in blabla.php on line 10

But if I understood correctly (even though it may not be the case at that point) if it is changed to:

Code: [Select]

function foo($var)
{
    $var++;
}

$a=5;
call_user_func_array('foo', array(&$a));

it should raise the:

QuoteNotice: Call-time pass-by-reference has been deprecated; If you would like to pass it by reference, modify the declaration of call_integration_hook(). If you would like to enable call-time pass-by-reference, you can set allow_call_time_pass_reference to true in your INI file

Did I miss anything?

Re: pass by ref

Reply #1 – January 13, 2013, 07:06:10 am

So:

Code: [Select]

function foo($var)
{
    $var++;
}

$a=5;
call_user_func_array('foo', array(&$a));

is fine and

Code: [Select]

function foo($var)
{
    $var++;
}

$a=5;
call_user_func_array('foo', &$a);

is broken?...and what's the difference in practical terms?
What's the most appropriate approach?

Re: pass by ref

Reply #2 – January 31, 2013, 02:58:54 pm

The correct approach is that the receiving function should always indicate its requiring a reference, making the whole thing moot.

Also, the difference between using array(&$a) and &$a is quite important - &$a then needs to contain all the parameters you're sending, rather than being able to send multiple things through in a nicely delineated fashion.