Dec

11

PHP - Variable References

December 11, 2007 |

In PHP, references are how you create variable aliases. To make $Seinfeld an alias for the variable $funny_guy, use: 

$Seinfeld =& $funny_guy;

Let’s take a look at the example below to get a bettering unsderstanding of variable references: 

$reference = "Rock";
$aliase =& $reference;
$reference .= " rocks!";
print "\$aliase is $aliase<br />";
print "\$reference is $reference<br />";
$aliase = "Actor $aliase";
print "\$aliase is $aliase<br />";
print "\$reference is $reference";

By executing the code above, you will get the output like something below:

$aliase is Rock rocks!
$reference is Rock rocks!
$aliase is Actor Rock rocks!
$reference is Actor Rock rocks!

From the result, we can see two points: 1. If we update value of $reference, the value $aliase will be the same as the lasted updated $reference value. 2. If we update the value of $aliase, the value of $reference will also be updated. 

Functions can return values by reference (for example, to avoid copying large strings or arrays). For example: 

function &ret_ref() {
$var = "PHP";
echo  $var;
return $var;
}
$v =& ret_ref(  );

Note you need to use the & before the function name ret_ref().



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  1. dan » PHP - Variable References on December 16, 2007 4:12 am

    [...] Check it out! While looking through the blogosphere we stumbled on an interesting post today.Here’s a quick excerptIf we update value of $reference, the value $aliase will be the same as the lasted updated $reference value. 2. If we update the value of $aliase, the value of $reference will also be updated. Functions can return values by reference … [...]

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