return by reference

Anon

Hi,

The PHP book that I have doesn't talk about return by reference for some reason (although it does a lot about pass by reference).

Simply doing this "return &$x;" doesn't seem to work.

PHP supports it, doesn't it?
Can someone please show me a syntax?

Thanx. -Jin

Anon

Return by reference is bad programming. Because you define $x in local scope, it can't be returned by reference without going out of scope (I'm sure this is not exactly correct, but I think it points out the problem).

PHP4 supports reference counting which removes the speed bonus you might get in other programs by returning by reference. Instead, just return your variable/object by value and let php4 clean up the locally defined definition by decrementing a reference counter.

Anon

Thank you very much for the reply.

If I remember "correctly", C++ doesn't allow it but perl does, and I hoped PHP'd do as well.

Indeed, it can't be a good logic to define a var in a local scope and return its reference, but wonder how perl is ok with it.

So what I am doing is, rather than to return by reference, to define a var prior to the function call and pass it by reference.

Anyway, thank you very much for the tip.

-Jin

Anon

Actually, you are able to define a function that returns a reference to a variable or object. This is very useful when you want to find a particular object in an array or tree structure, and then perform a method which will change some of its values. Rather than doing it in the return line, you precede both the function definition and call with a "&".

e.g.
<?php
$barArray = Array(10,20,30);

$bar = &foo(1);
$bar++;
echo $barArray[1]; // echos 21

function &foo($bar){
global $barArray;
return $barArray[$bar];
}
?>

Anon

check this page...about half way down?

http://www.php.net/manual/en/functions.returning-values.php

J W Choi wrote:

Hi,

The PHP book that I have doesn\\'t talk about return by reference for some reason (although it does a lot about pass by reference).

Simply doing this \\"return &$x;\\" doesn\\'t seem to work.

PHP supports it, doesn\\'t it?
Can someone please show me a syntax?

Thanx. -Jin