- var_export: documentation ( source)
<?php
$a = [
'color' => 'red',
'taste' => 'sweet',
'shape' => 'round',
'name' => 'apple'
];
$a += ['myKey' => 'foo']; // this is added because the key doesn't exist
$a += ['shape' => 'bar']; // this is ignored because the already key exists
$a += ['zero']; // this is added because the 0 key doesn't exist
$a += ['not zero']; // this is ignored because the 0 key already exists
var_export($a);