PHP - Returning References from Your Own Functions

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Introduction

You can get functions to return references, rather than values.

To do this, you place an ampersand before the function name in your function definition.

Then, when you return a variable with the return statement, you pass a reference to that variable back to the calling code, rather than the variable's value: 

function  & myFunc(){
   // (do stuff)
   return $var;  // Returns a reference to $var
}

Here's an example that shows return-by-reference in action:

Demo

<?php

$myNumber = 5;/*from   w ww  . j a va  2s .c  o  m*/

function  & getMyNumber() {
    global $myNumber;
    return $myNumber;
}

$numberRef = &  getMyNumber();
$numberRef++;
echo"\$myNumber = $myNumber \n";   // Displays"6"
echo"\$numberRef = $numberRef \n"; // Displays"6"
?>

Result

First, a global variable, $myNumber, is created and given the value 5.

Next, a function, getMyNumber(), is defined.

This function uses the global keyword to access the global variable $myNumber, then returns $myNumber.

Because getMyNumber() has an ampersand before its name, it returns a reference to $myNumber, rather than the value that $myNumber holds.

Next, the script calls getMyNumber().

The return value of getMyNumber() - that is, the reference to $myNumber - is then assigned to a new variable, $numberRef.

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