- http_build_query: documentation ( source)
<?php
$query_string = [
'one' => 1,
'two' => '',
'three' => null, // gets omitted
'four' => ' ', // gets encoded
'five' => "&test=test" // gets encoded
];
echo http_build_query($query_string);
echo "\n---\n";
echo http_build_query($query_string, '', '&');
echo "\n\n\n\n\n";