You can multiple ways how to add values into an array. When using an array_push(), the specific values are added into array.
To add specific keys and values into an array, you have to set keys in variable:
$arr = array();
$arr['name'] = 'Florian';
$arr['surname'] = 'Baker';
This array will look like:
array( 'name' => 'Florian' , 'surname' => 'Baker' );