<?php
$data = array(
    'Hello' => 'World',
    'person' => array(
        'name' => array(
            'first' => 'David',
            'last' => 'Stensland'
        ),
        'age' => 20
    )
);

var_dump(http_build_query($data));
#> Hello=World&person%5Bname%5D%5Bfirst%5D=David&person%5Bname%5D%5Blast%5D=Stensland&person%5Bage%5D=20