- var_dump: documentation ( source)
- array_merge: documentation ( source)
<?php
$source = [
0=>[
['foo'=>['bar']]],
1=>[
['biz'=>'baz'],
['a'=>'b']]
];
$return = [];
foreach($source as $dataset) {
$return = array_merge($return, $dataset);
}
var_dump($return);