Within a class, passing array elements by reference which don't exist are added to the array as null. Compared to a normal function, this changes the behavior of the function from throwing an error to creating a new (null) entry in the referenced array with a new key.
<?php
class foo {
public $arr = ['a' => 'apple', 'b' => 'banana'];
public function normalFunction($key) {
return $this->arr[$key];
}
public function &referenceReturningFunction($key) {
return $this->arr[$key];
}
}
$bar = new foo();
$var = $bar->normalFunction('beer'); $var = &$bar->referenceReturningFunction('beer'); var_dump($bar->arr);
?>
This is in no way a "bug" - the framework is performing as designed, but it took careful thought to figure out what was going on. PHP7.3
