Why is function call by reference in PHP deprecated?

Question

I wrote the following code:

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Answer 1

This is all documented on the PHP Passing by Reference manual page. Specifically (added emphasis mine):

Note: There is no reference sign on a function call - only on function definitions. Function definitions alone are enough to correctly pass the argument by reference. As of PHP 5.3.0, you will get a warning saying that "call-time pass-by-reference" is deprecated when you use & in foo(&$a);. And as of PHP 5.4.0, call-time pass-by-reference was removed, so using it will raise a fatal error.

As such, it was deprecated (and will throw a warning) in PHP 5.3.x and will fail in PHP 5.4.

That said, it's a trivial fix. Simply update your fix_names function as follows:

function fix_names(&$n1, &$n2, &$n3)
{
    $a1 = ucfirst(strtolower($n1));
    $a2 = ucfirst(strtolower($n2));
    $a3 = ucfirst(strtolower($n3));

}

Incidentally, the 5.3.x series is getting quite long in the tooth, so it would be wise to update to a more recent build (after carrying out the necessary testing) if at all possible.

Answer 2

use this....

fix_names(&$a1, &$a2, &$a3);

Answer 3

Remove the & symbols from your like: &$n1, &$n2, ...