====== Passing by Reference ======

Explained better by this [[https://www.php.net/manual/en/language.references.pass.php|PHP article]].

Passing a parameter by reference is useful if you want to pass a parameter and edit it without having to return it.

You define a parameter with reference with the ''&'' symbol like so:

<code php>

$johnLennon = [
  'alive' => true,
  'name' => 'John Lennon',
];

function kill(array &$toBeKilled): void 
{
  $toBeKilled['alive'] = false;
}

kill($johnLennon);

// John Lennon now looks like this:
// $johnLennon = [
//   'alive' => false,
//   'name' => 'John Lennon',
// ];
debug($johnLennon);

</code>

Many PHP array functions also use this, so you don't have to keep overwriting your variables after doing an action on the array like adding an element. Example [[https://www.php.net/manual/en/function.array-unshift.php|array_unshift]].