Params with null value do not present in result string.
<?php
$arr = array('test' => null, 'test2' => 1);
echo http_build_query($arr);
?>
will produce:
test2=1
(PHP 5, PHP 7, PHP 8)
http_build_query — URL エンコードされたクエリ文字列を生成する
$data,$numeric_prefix = "",$arg_separator = null,$encoding_type = PHP_QUERY_RFC1738与えられた連想配列 (もしくは添字配列) から URL エンコードされたクエリ文字列を生成します。
dataプロパティを含む配列もしくはオブジェクト。
data が配列の場合の形式は、
単純な一次元構造か
あるいは配列の配列 (言い換えると、他の配列を含む配列) となります。
data がオブジェクトの場合、
public プロパティだけが結果に含められます。
numeric_prefix
情報源となる配列 (query_data で指定した配列)
に数値インデックスが使われていて、しかも numeric_prefix
が指定された場合、数値のインデックスを持つ要素に関してのみインデックスの前に
numeric_prefix で指定した値が付加されます。
これは、後で PHP や他の CGI アプリケーションによってデータがデコードされる際、 正当な変数名になるよう考慮したものです。
arg_separator
引数のセパレータ。指定されていなかったり、null だった場合は、
arg_separator.output
が区分のためのセパレータとして使用されます。
encoding_type
デフォルトは PHP_QUERY_RFC1738 です。
encoding_type が
PHP_QUERY_RFC1738 の場合は
» RFC 1738 に従ってエンコードされ、メディアタイプは
application/x-www-form-urlencoded となります。
つまり、スペースはプラス記号 (+) にエンコードされるということです。
encoding_type が
PHP_QUERY_RFC3986 の場合は
» RFC 3986 に従ってエンコードされ、
スペースはパーセント形式 (%20) となります。
URL エンコードされた文字列を返します。
例1 http_build_query() の簡単な使用法
<?php
$data = array(
'foo' => 'bar',
'baz' => 'boom',
'cow' => 'milk',
'null' => null,
'php' => 'hypertext processor'
);
echo http_build_query($data) . "\n";
echo http_build_query($data, '', '&');
?>上の例の出力は以下となります。
foo=bar&baz=boom&cow=milk&php=hypertext+processor foo=bar&baz=boom&cow=milk&php=hypertext+processor
例2 数値インデックス要素の場合での http_build_query()
<?php
$data = array('foo', 'bar', 'baz', null, 'boom', 'cow' => 'milk', 'php' => 'hypertext processor');
echo http_build_query($data) . "\n";
echo http_build_query($data, 'myvar_');
?>上の例の出力は以下となります。
0=foo&1=bar&2=baz&4=boom&cow=milk&php=hypertext+processor myvar_0=foo&myvar_1=bar&myvar_2=baz&myvar_4=boom&cow=milk&php=hypertext+processor
例3 複雑な配列の場合での http_build_query()
<?php
$data = array(
'user' => array(
'name' => 'Bob Smith',
'age' => 47,
'sex' => 'M',
'dob' => '5/12/1956'
),
'pastimes' => array('golf', 'opera', 'poker', 'rap'),
'children' => array(
'bobby' => array('age'=>12, 'sex'=>'M'),
'sally' => array('age'=>8, 'sex'=>'F')
),
'CEO'
);
echo http_build_query($data, 'flags_');
?>上の例は以下を出力します: (可読性のため適宜折り返しています)
user%5Bname%5D=Bob+Smith&user%5Bage%5D=47&user%5Bsex%5D=M& user%5Bdob%5D=5%2F12%2F1956&pastimes%5B0%5D=golf&pastimes%5B1%5D=opera& pastimes%5B2%5D=poker&pastimes%5B3%5D=rap&children%5Bbobby%5D%5Bage%5D=12& children%5Bbobby%5D%5Bsex%5D=M&children%5Bsally%5D%5Bage%5D=8& children%5Bsally%5D%5Bsex%5D=F&flags_0=CEO
注意:
基底の配列内の数値インデックス要素 "CEO" のみ、 接頭辞を受け取ります。pastimes 以下にある他の数値インデックスは、 正当な変数名にするための文字列の接頭辞を要求しません。
例4 オブジェクトの場合の http_build_query() の使用
<?php
class parentClass {
public $pub = 'publicParent';
protected $prot = 'protectedParent';
private $priv = 'privateParent';
public $pub_bar = null;
protected $prot_bar = null;
private $priv_bar = null;
public function __construct(){
$this->pub_bar = new childClass();
$this->prot_bar = new childClass();
$this->priv_bar = new childClass();
}
}
class childClass {
public $pub = 'publicChild';
protected $prot = 'protectedChild';
private $priv = 'privateChild';
}
$parent = new parentClass();
echo http_build_query($parent);
?>上の例の出力は以下となります。
pub=publicParent&pub_bar%5Bpub%5D=publicChild
Params with null value do not present in result string.
<?php
$arr = array('test' => null, 'test2' => 1);
echo http_build_query($arr);
?>
will produce:
test2=1Passing null to $arg_separator is the same as passing an empty string, which is probably not what you want.
If you need to change the enc_type, use this:
http_build_query($query, null, '&', PHP_QUERY_RFC3986);
Or possibly this:
http_build_query($query, null, ini_get('arg_separator.output'), PHP_QUERY_RFC3986);
But not this:
// BAD CODE!
http_build_query($query, null, null, PHP_QUERY_RFC3986);This function makes like this
files[0]=1&files[1]=2&...
To do it like this:
files[]=1&files[]=2&...
Do this:
$query = http_build_query($query);
$query = preg_replace('/%5B[0-9]+%5D/simU', '%5B%5D', $query);if you send boolean values it transform in integer :
$a = [teste1= true,teste2=false];
echo http_build_query($a)
//result will be teste1=1&teste2=0Number to string conversion occured in <?php http_build_query() ?> is affected by locale settings, which might not be obvious.
<?php
$params = ["v" => 5.63];
setlocale(LC_ALL, 'us_En');
http_build_query($params) // v=5.63
setlocale(LC_ALL, 'ru_RU');
http_build_query($params) // v=5,63 mind the comma
?>As noted before, with php5.3 the separator is & on some servers it seems. Normally if posting to another php5.3 machine this will not be a problem.
But if you post to a tomcat java server or something else the & might not be handled properly.
To overcome this specify:
http_build_query($array, '', '&');
and NOT
http_build_query($array); //gives & to some serversIf you need the inverse functionality, and (like me) you cannot use pecl_http, you may want to use something akin to the following.
<?php function http_parse_query($Query) {
// mimic the behavior of $_GET, see also RFC 1738 and 3986.
$Delimiter = ini_get('arg_separator.input');
$Params = array();
foreach (explode($Delimiter, $Query) as $NameValue) {
preg_match(
'/^(?P<name>[^=\[]*)(?P<indices_present>\[(?P<indices>[^\]]*(\]\[[^\]]*)*)\]?)?(?P<value_present>=(?P<value>.*))?$/',
$NameValue,
$NameValueParts
);
if (!empty($NameValueParts)) {
$Param =& $Params[$NameValueParts['name']];
if (!empty($NameValueParts['indices_present'])) {
$Indices = explode('][', $NameValueParts['indices']);
foreach ($Indices as $Index) {
if (!is_array($Param)) {
$Param = array();
}
if ($Index === '') {
$Param[] = array();
end($Param);
$Param =& $Param[key($Param)];
} else {
if (ctype_digit($Index)) { $Index = (int) $Index; }
if (!array_key_exists($Index, $Param)) {
$Param[$Index] = array();
}
$Param =& $Param[$Index];
}
}
}
if (!empty($NameValueParts['value_present'])) {
$Param = urldecode($NameValueParts['value']);
} else {
$Param = '';
}
}
}
return $Params;
}?>Is it worth noting that if query_data is an associative array and a value is itself an empty array, or an array of nothing but empty array (or arrays containing only empty arrays etc.), the corresponding key will not appear in the resulting query string?
E.g.
$post_data = array('name'=>'miller', 'address'=>array('address_lines'=>array()), 'age'=>23);
echo http_build_query($post_data);
will print
name=miller&age=23Be careful about Example 1 -- it is exactly how *not* to implement things.
& as a separator is the URL encoding.
& is HTML encoding.
You should HTML encode your URL if embedding it in a web page. This is more involved than just replacing & with &. Doing as this example suggests is a security hole waiting to happen.When using the http_build_query function to create a URL query from an array for use in something like curl_setopt($ch, CURLOPT_POSTFIELDS, $post_url), be careful about the url encoding.
In my case, I simply wanted to pass on the received $_POST data to a CURL's POST data, which requires it to be in the URL format. If something like a space [ ] goes into the http_build_query, it comes out as a +. If you're then sending this off for POST again, you won't get the expected result. This is good for GET but not POST.
Instead you can make your own simple function if you simply want to pass along the data:
<?php
$post_url = '';
foreach ($_POST AS $key=>$value)
$post_url .= $key.'='.$value.'&';
$post_url = rtrim($post_url, '&');
?>
You can then use this to pass along POST data in CURL.
<?php
$ch = curl_init($some_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_url);
curl_exec($ch);
?>
Note that at the final page that processes the POST data, you should be properly filtering/escaping it.As noted, this function omits keys with null values. This could break some code which treats the key as boolean, and so has no value, or other code expecting the array to be populated regardless of value.
A workaround for this is to replace the null values with an empty string:
$data=array(
'a'=>'apple',
'b'=>2,
'c'=>null,
'd'=>'…',
);
// Compensate for fact that http_build_query omits null values
foreach($data as &$datum) if($datum===null) $datum='';
Losing the null-ness of the original is no real loss if it’s supposed to be a real query string. If the null is important, you could use a dummy value instead.
MarkCorrect implementation of coding the array of params without indexes (valdikks fixed code - didnt work for inner arrays):
<code>
function cr_post($a,$b='',$c=0)
{
if (!is_array($a)) return false;
foreach ((array)$a as $k=>$v)
{
if ($c)
{
if( is_numeric($k) )
$k=$b."[]";
else
$k=$b."[$k]";
}
else
{ if (is_int($k))
$k=$b.$k;
}
if (is_array($v)||is_object($v))
{
$r[]=cr_post($v,$k,1);
continue;
}
$r[]=urlencode($k)."=".urlencode($v);
}
return implode("&",$r);
}
</code>When using http_build_query($args) where $args is an array; note that there is a limit to the size of array. See max_input_vars in your php.ini to increase this size.I noticed that even with the magic quotes disabled, http_build_query() automagically adds slashes to strings.
So, I had to add "stripslashes" to every string variable.on my install of PHP 5.3, http_build_query() seems to use & as the default separator. Kind of interesting when combined with stream_context_create() for a POST request, and getting $_POST['amp;fieldName'] on the receiving end.Warning: Different arrays may return the same result
<CODE>
$a1 = array('x[y]' => array('a'=>1));
$a2 = array('x' => array('y' => array('a'=>1)));
$q1 = http_build_query($a1);
$q2 = http_build_query($a2);
var_dump($a1);
echo '<BR>';
var_dump($a2);
echo '<BR>';
echo $q1;
echo '<BR>';
echo $q2;
echo '<BR>';
</CODE>
Result:
array(1) { ["x[y]"]=> array(1) { ["a"]=> int(1) } }
array(1) { ["x"]=> array(1) { ["y"]=> array(1) { ["a"]=> int(1) } } }
x%5By%5D%5Ba%5D=1
x%5By%5D%5Ba%5D=1It's not mentioned in the documentation, but when calling http_build_query on an object, public null fields are ignored.
<?php
class A {
public int $publicNotNull;
public ?int $publicNull;
private string $privateNotNull;
public function __construct()
{
$this->publicNotNull = 2;
$this->privateNotNull = "Test";
}
}
$a = new A();
echo http_build_query($a); // publicNotNull=2
?>While http_build_query can also be used to encode most classes, into a query string, SimpleXML Elements with <![CDATA[]]> values are picked up as empty arrays, and therefore aren't included naturally.
<?php
$xml = simplexml_load_string( '<wrapper><key><![CDATA[value]]></key><key2>value2</key2></wrapper>' );
var_dump( $xml, http_build_query( $xml ) );
/* Outputs:
object(SimpleXMLElement)#1 (2) {
["key"]=>
object(SimpleXMLElement)#2 (0) {
}
["key2"]=>
string(6) "value2"
}
string(11) "key2=value2"
*/
?>