Please consider using the the latest stable version for any production code.

The QueryParser

To preserve the query string, the library does not rely on PHP’s parse_str and http_build_query functions.

Instead, the League\Uri\QueryParser class provides two public methods that can be used to parse a query string into an array of key value pairs. And conversely creates a valid query string from the resulting array.

Parsing the query string into an array

<?php

public QueryParser::parse(string $query_string [, string $separator = '&' [, int $encoding = RFC3986]]): array

The QueryParser::parse method returns an array representation of the query string which preserve key/value pairs. The method expects at most 3 arguments:

• The query string;
• The query string separator, by default it is set to &;
• The query string encoding. It can be:
  • PHP_QUERY_RFC3986
  • PHP_QUERY_RFC1738
  • false if you don’t want any encoding.

By default or if the submitted encoding is invalid the encoding is set to PHP constant PHP_QUERY_RFC3986

The other encoding styles are deprecated and will be removed in the next major release. You should not rely on them.

<?php

use League\Uri\QueryParser;

$parser = new QueryParser();
$query_string = 'toto.foo=bar&toto.foo=baz';
$arr = $parser->parse($query_string, '&', PHP_QUERY_RFC3986);
// $arr is an array containing ["toto.foo" => ["bar", "baz"]]

Main differences with parse_str:

• parse_str replaces any invalid characters from the query string pair key that can not be included in a PHP variable name by an underscore _.
• parse_str merges query string values.

These behaviors, specific to PHP, may be considered to be a data loss transformation in other languages.

<?php

$query_string = 'toto.foo=bar&toto.foo=baz';
parse_str($query_string, $arr);
// $arr is an array containing ["toto_foo" => "baz"]

Building the query string from an array

<?php

public QueryParser::build(array $data [, string $separator = '&' [, int $encoding = RFC3986]]): string

The QueryParser::build method returns and preserves string representation of the query string from the QueryParser::parse array result. The method expects at most 3 arguments:

• A valid array of data to convert;
• The query string separator, by default it is set to &;
• The query string encoding. It can be:
  • PHP_QUERY_RFC3986
  • PHP_QUERY_RFC1738
  • false if you don’t want any encoding.

By default or if the submitted encoding is invalid the encoding is set to PHP constant PHP_QUERY_RFC3986

The other encoding styles are deprecated and will be removed in the next major release. You should not rely on them.

<?php

use League\Uri\QueryParser;

$query_string = 'foo[]=bar&foo[]=baz';
$parser = new QueryParser();
$arr = $parser->parse($query_string, '&', PHP_QUERY_RFC3986);
var_export($arr);
// $arr include the following data ["foo[]" => ['bar', 'baz']];

$res = $parser->build($arr, '&', false);
// $res = 'foo[]=bar&foo[]=baz'

No key indexes are added and the query string is safely recreated

Main differences with http_build_query:

http_build_query always adds array numeric prefix to the query string even when they are not needed.

using PHP’s parse_str

<?php

$query_string = 'foo[]=bar&foo[]=baz';
parse_str($query_string, $arr);
// $arr = ["foo" => ['bar', 'baz']];

$res = rawurldecode(http_build_query($arr, '', '&', PHP_QUERY_RFC3986));
// $res equals foo[0]=bar&foo[1]=baz

or using QueryParser::parse

<?php

use League\Uri\QueryParser;

$query_string = 'foo[]=bar&foo[]=baz';
$parser = new QueryParser();
$arr = $parser->parse($query_string, '&', PHP_QUERY_RFC3986);
// $arr = ["foo[]" => ['bar', 'baz']];

$res = rawurldecode(http_build_query($arr, '', '&', PHP_QUERY_RFC3986));
// $res equals foo[][0]=bar&foo[][1]=baz