Passing by Reference

Passing by Reference

You can pass a variable by reference to a function so the function can modify the variable. The syntax is as follows:

<?php

function foo(&$var)
{
  $var++;
}

$a=5;

foo($a);
// $a is 6 here

?>

Opmerking: > 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.

The following things can be passed by reference:

• Variables, i.e. foo($a)

• References returned from functions, i.e.: See more about . php <?php function foo(&$var) { $var++; } function &bar() { $a = 5; return $a; } foo(bar()); ?> returning by reference

  No other expressions should be passed by reference, as the result is undefined. For example, the following examples of passing by reference are invalid: