Класс ArrayObject
(PHP 5, PHP 7)
Введение
Данный класс позволяет работать с объектами как с массивами.
Обзор классов
/* Константы */
/* Методы */
public __construct
([ mixed
}$input = []
[, int $flags = 0
[, string $iterator_class = "ArrayIterator"
]]] )Предопределенные константы
Опции ArrayObject
ArrayObject::STD_PROP_LIST-
Свойства объекта получают стандартное поведение, при доступе к объекту как к списку (var_dump, foreach и т.д.).
ArrayObject::ARRAY_AS_PROPS-
Записи могут быть доступны как свойства (для чтения и записи).
Содержание
- ArrayObject::append — Добавляет значение в конец массива
- ArrayObject::asort — Сортирует записи по значению
- ArrayObject::__construct — Создает новый объект типа массив
- ArrayObject::count — Возвращает количество публичных свойств ArrayObject
- ArrayObject::exchangeArray — Заменяет текущий массив на другой
- ArrayObject::getArrayCopy — Создаёт копию ArrayObject
- ArrayObject::getFlags — Получает флаги поведения
- ArrayObject::getIterator — Создаёт новый итератор из экземпляра ArrayObject
- ArrayObject::getIteratorClass — Возвращает имя класса итератора для ArrayObject
- ArrayObject::ksort — Сортирует записи по ключам
- ArrayObject::natcasesort — Сортирует массив, используя регистронезависимый алгоритм "natural order"
- ArrayObject::natsort — Сортирует массив, используя алгоритм "natural order"
- ArrayObject::offsetExists — Проверяет, существует ли указанный индекс
- ArrayObject::offsetGet — Возвращает значение по указанному индексу
- ArrayObject::offsetSet — Устанавливает новое значение по указанному индексу
- ArrayObject::offsetUnset — Удаляет значение по указанному индексу
- ArrayObject::serialize — Сериализует ArrayObject
- ArrayObject::setFlags — Устанавливает флаги поведения
- ArrayObject::setIteratorClass — Устанавливает имя класса итератора для ArrayObject
- ArrayObject::uasort — Сортирует записи, используя пользовательскую функцию для сравнения элементов и сохраняя при этом связь ключ/значение
- ArrayObject::uksort — Сортирует массив по ключам, используя пользовательскую функцию для сравнения
- ArrayObject::unserialize — Десериализует ArrayObject
Коментарии
Too bad the Array functions [1] are not available on this object… otherwise I would be using it all the time.
[1] http://nl.php.net/manual/en/ref.array.php
If you want to use array functions on an ArrayObject, why not use iterator_to_array() to get a standard PHP array? Do your operations on that array, then instantiate a new ArrayObject, passing it the array.
This might be a little slow on large ArrayObjects, but you'd have access to all of the array functions.
Simple example of usage :
<?php
$array = array('Buck','Jerry','Tomas');
$arrayObject = new ArrayObject($array);
// Add new element
$arrayObject->append('Tweety');
// We are getting the iterator of the object
$iterator = $arrayObject->getIterator();
// Simple while loop
while ($iterator->valid()) {
echo $iterator->current() . "\n";
$iterator->next();
}
/* Outputs */
Buck
Jerry
Tomas
Tweety
?>
Note that not all the public methods of this class are documented here .
( Which includes a lot sorting methods ) .
Regards
Generally variable $this can't be used as an array within an object context. For example, following code piece would cause a fatal error:
<?php
class TestThis {
public function __set($name, $val) {
$this[$name] = $val;
}
public function __get($name) {
return $this[$name];
}
}
$obj = new TestThis();
$obj->a = 'aaa';
echo $obj->a . "\n";
?>
But things are different when $this is used in an ArrayObject object. e.g., following code piece are valid:
<?php
class TestArrayObject extends ArrayObject {
public function __set($name, $val) {
$this[$name] = $val;
}
public function __get($name) {
return $this[$name];
}
}
$obj = new TestArrayObject();
$obj->a = 'aaa';
echo $obj->a . "\n";
?>
According to my benchmarks, doing foreach() on an ArrayObject is significantly slower than doing so on a vanilla array(). However, inserting keys and retrieving them is almost the same speed.
So, if performance is important, consider not using ArrayObject or descendant classes when you're iterating over its values a lot.
These are my timing results, using PEAR::Benchmark:
ArrayObject fill 0.01441502571106
ArrayObject read_key 0.018320083618164
ArrayObject read_foreach 2.1559031009674
array() fill 0.012364864349365
array() read_key 0.013092041015625
array() read_foreach 0.011217832565308
In all cases, 'fill()' inserts 10000 numbers at string keys, 'read_key()' reads all of those values by referencing the keys, and 'read_foreach()' does the same by walking through the array(object) with foreach().
As you can see, filling or reading from an ArrayObject by key is only 10% to 15% slower, but doing a foreach() is 200 times as costly. I am not sure what the cause of this may be.
To implement array-style appending (e.g. "$object[] = 'foo';") in your own class implementing the ArrayAccess _interface_, all you need do is check if the key passed to your implementation of offsetSet() is NULL. Something like the following.
<?php
class MyArrayObject implements ArrayAccess {
/**
* @var array
*/
private $aValue;
// ...
/**
* @see ArrayAccess::offsetSet()
*/
public function offsetSet ($p_key, $p_value) {
if (is_null($p_key)) {
$this->aValue[] = $p_value;
}
else {
$this->aValue[$p_key] = $p_value;
}
}
// ...
}
?>
I don't believe the same performance is true since PHP 5.3. Using the same fill, read_key and foreach approach on both native arrays and ArrayObjects with 10000 keys I get the following
PHP 5.2
array() fill 0.013101
array() read 0.008685
array() foreach 0.004319
ArrayObject fill 0.014136
ArrayObject read 0.010003
ArrayObject foreach 3.454612
PHP 5.3
array() fill 0.010395
array() read 0.005933
array() foreach 0.001903
ArrayObject fill 0.010598
ArrayObject read 0.006387
ArrayObject foreach 0.003451
This was the code I used for both, an array or ArrayObject is passed into each of the functions. Again PEAR::Benchmark was used to get the results.
<?php
require_once 'Benchmark/Timer.php';
define('KEYS', 10000);
function fill(&$arr) {
for ($i = 1; $i <= KEYS; $i++) {
$arr['key-' . $i] = $i;
}
}
function read_key(&$arr) {
for ($i = 1; $i <= KEYS; $i++) {
$v = $arr['key-' . $i];
}
}
function fe(&$arr) {
foreach ($arr as $key => $value) {
$v = $value;
}
}
?>
If you plan to derive your own class from ArrayObject, and wish to maintain complete ArrayObject functionality (such as being able to cast to an array), it is necessary to use ArrayObject's own private property "storage".
Since that is impossible to do directly, you must use ArrayObject's offset{Set,Get,Exists,Unset} methods to manipulate it indirectly.
As a side benefit, this means you inherit all the iteration and other functions in complete working order.
This may sound obvious to someone who has never implemented their own ArrayObject class... but it is far from so.
<?php
class MyArrayObject extends ArrayObject {
static $debugLevel = 2;
static public function sdprintf() {
if (static::$debugLevel > 1) {
call_user_func_array("printf", func_get_args());
}
}
public function offsetGet($name) {
self::sdprintf("%s(%s)\n", __FUNCTION__, implode(",", func_get_args()));
return call_user_func_array(array(parent, __FUNCTION__), func_get_args());
}
public function offsetSet($name, $value) {
self::sdprintf("%s(%s)\n", __FUNCTION__, implode(",", func_get_args()));
return call_user_func_array(array(parent, __FUNCTION__), func_get_args());
}
public function offsetExists($name) {
self::sdprintf("%s(%s)\n", __FUNCTION__, implode(",", func_get_args()));
return call_user_func_array(array(parent, __FUNCTION__), func_get_args());
}
public function offsetUnset($name) {
self::sdprintf("%s(%s)\n", __FUNCTION__, implode(",", func_get_args()));
return call_user_func_array(array(parent, __FUNCTION__), func_get_args());
}
}
$mao = new MyArrayObject();
$mao["name"] = "bob";
$mao["friend"] = "jane";
print_r((array)$mao);
/* Output:
offsetSet(name,bob)
offsetSet(friend,jane)
Array
(
[name] => bob
[friend] => jane
) */
?>
If you wish to use the "Array as Properties" flag, you simply need to include this in your constructor:
<?php parent::setFlags(parent::ARRAY_AS_PROPS); ?>
This will allow you to do things such as the below example, without overriding __get or __set .
<?php
$mao->name = "Phil";
echo $mao["name"]; /* Outputs "Phil" */
?>
A gotcha that is indeed mentioned in the manual, but isn't readily obvious and just cost me half an hour:
Objects implementing the Serializable interface do NOT get __sleep and __wakeup called; instead, they use serialize and unserialize methods, respectively (why, I don't know, but whatever - I'm sure there's a reason).
Hence, I was trying to serialize a database resultset in an object extending ArrayObject, and needed to fix some stuff regarding database resources on serialize. Took me a while to figure out __sleep wasn't getting called because ArrayObjects implements Serialize...
Presumably the ArrayObject internally implements the serialize/unserialize methods (in a trivial manner), hence the error wasn't apparent immediately (i.e., no fatal error was thrown) and I'd been trying to track why my objects didn't get serialized (they were of course) instead of renaming and fixing the methods.
I found the description of STD_PROP_LIST a bit vague, so I put together a simple demonstration to show its behavior:
<?php
$a = new ArrayObject(array(), ArrayObject::STD_PROP_LIST);
$a['arr'] = 'array data';
$a->prop = 'prop data';
$b = new ArrayObject();
$b['arr'] = 'array data';
$b->prop = 'prop data';
// ArrayObject Object
// (
// [prop] => prop data
// )
print_r($a);
// ArrayObject Object
// (
// [arr] => array data
// )
print_r($b);
?>
As you know ArrayObject is not an array so you can't use the built in array functions. Here's a trick around that:
Extend the ArrayObject class with your own and implement this magic method:
<?php
public function __call($func, $argv)
{
if (!is_callable($func) || substr($func, 0, 6) !== 'array_')
{
throw new BadMethodCallException(__CLASS__.'->'.$func);
}
return call_user_func_array($func, array_merge(array($this->getArrayCopy()), $argv));
}
?>
Now you can do this with any array_* function:
<?php
$yourObject->array_keys();
?>
- Don't forget to ommit the first parameter - it's automatic!
Note: You might want to write your own functions if you're working with large sets of data.
Long story short b/c arrays by default are passed by value, if you pass an array to a function, the function works on a copy of the array while the original array remains unaltered by the function.
You may cause a change to the array to be reflected in the original array by having the function return the altered array and assign it to the variable for the original array, as follows:
<?php
function my_array_modify($data) {
$data['b'] = 2;
return $data;
}
$regularArray = array();
$regularArray['a'] = 1;
$regularArray = my_array_modify($regularArray);
var_dump($regularArray['b']); // 2
?>
Or, you may explicitly pass the array by reference in which case there is no need for the function to return the array since the change will have effected the original array, as follows:
<?php
function my_arrayref_modify(&$data) {
$data['bb'] = 22;
}
my_arrayref_modify($regularArray);
var_dump($regularArray['bb']); // 22
?>
There is a better explanation about the ArrayObject flags (STD_PROP_LIST and ARRAY_AS_PROPS) right here:
http://stackoverflow.com/a/16619183/1019305
Thanks to JayTaph
// Example STD_PROP_LIST and ARRAY_AS_PROP combined
<?php
$ao = new ArrayObject();
$ao ->setFlags(ArrayObject::STD_PROP_LIST|ArrayObject::ARRAY_AS_PROPS);
$ao->prop = 'prop data';
$ao['arr'] = 'array data';
print_r($ao);
?>
// Result
ArrayObject Object
(
[storage:ArrayObject:private] => Array
(
[prop] => prop data
[arr] => array data
)
)
<?php
class Prototype extends ArrayObject
{
private $___class = null;
public function __get($key)
{
return $this[$key];
}
public function __set($key, $value)
{
$this[$key] = $value;
}
public function __call($key, $args)
{
if(is_object($this->___class) && is_callable([$this->___class, $key])){
return call_user_func_array([$this->___class, $key],$args);
}
return is_callable($c = $this->__get($key)) ? call_user_func_array($c, $args) : null;
}
public function importObj($class, $array = []){
$this->___class = $class;
if(count($array) > 0){
$this->import($array);
}
return $this;
}
public function import($input)
{
$this->exchangeArray($input);
return $this;
}
public function export()
{
return $this->objectToArray($this->getArrayCopy());
}
public function objectToArray ($object) {
$o = [];
foreach ($object as $key => $value) {
$o[$key] = is_object($value) ? (array) $value: $value;
}
return $o;
}
}
class user{
public $name = 'Mahmoud Elnezamy';
public function getName(){
return 'You Name is ' . $this->name;
}
}
//usage you can import object with some array
$add = ['age' => '27', 'country' => 'Egypt'];
$user = new user;
$Prototype = new Prototype;
$Prototype->importObj($user, $add);
//print_r($Prototype);
echo $Prototype->getName().' ';
echo $Prototype->age.' ';
echo $Prototype->country;
If you want numerical ArrayObject objects to play nice with json_encode(), implement JsonSerializable:
class JsonSerializableArrayObject extends ArrayObject implements JsonSerializable {
function jsonSerialize() {
return $this->getArrayCopy();
}
}
For assoc ArrayObject objects this isn't neccesary, but for numerical arrays it is, otherwise they will be formatted like
{"0":"jaap","1":"karel"}
instead of
["jaap","karel"]
You can easily realise that ArrayObject can use various functions as they are in ArrayIterator to iterate an object-as-a-array. However, you need to "activate" these function (rewind, valid, next and so on...) by using getIterator() first. Actually this function inherits from Iterator Aggregate interface.
Take a look at the following basic example. The results are the same:
<?php
$array = [1, 2, 3, 4];
$a = new ArrayObject($array);
$b = new ArrayIterator($array);
$iterator = $a->getIterator();
for($iterator->rewind(); $iterator->valid(); $iterator->next()){
echo $iterator->current()*2;
}
for($b->rewind(); $b->valid(); $b->next()){
echo $b->current()*2;
}
//Resulst are the same 2468 AND 2468
class RecursiveArrayObject extends \ArrayObject
{
public function __construct($input = array())
{
$data = array();
foreach ($input as $key => $value) {
if (is_array($value)) {
$value = new self($value);
}
$data[$key] = $value;
}
parent::__construct($data, \ArrayObject::ARRAY_AS_PROPS);
}
}
$company = new RecursiveArrayObject(array(
'ceo' => array(
'id' => 1,
'name' => 'tony',
'age' => 36
),
'coo' => array(
'id' => 2,
'name' => 'matt',
'age' => 35
),
'cto' => array(
'id' => 3,
'name' => 'james',
'age' => 35
)
));
var_dump($company->cto->name); // string(5) "james"
var_dump($company['coo']['name']); // string(4) "matt"
function map_of_array(array $element, $callable)
{
foreach ($element as $key => $value) {
$callable($key, $value);
}
}
Usage:
$key_values = ["name" => "krisna", "level" => 10];
map_of_array($key_values, function ($key, $value) {
echo "\n", $key, "=", $value;
});
Result:
name=krisna
level=10
If you want to use built-in array function with ArrayObject, store the iterator instance and return the value as reference in offsetGet.
<?php
class Collection extends \ArrayObject {
public function __construct(array $data = [])
{
if (!\is_array($data) && !\array_key_exists('ArrayAccess', class_implements($data))) {
$data = [$data];
}
$this->iterator = $this->getIterator();
parent::__construct($data);
}
public function &offsetGet($index)
{
$value = &$this->iterator[$index] ?? null;
return $value;
}
}
?>
Differences between STD_PROP_LIST and ARRAY_AS_PROPS
<?php
$a = new ArrayObject([], ArrayObject::STD_PROP_LIST);
$a['arr'] = 'Array data';
$a->prop = 'Prop data';
$b = new ArrayObject([], ArrayObject::ARRAY_AS_PROPS);
$b['arr'] = 'Array data';
$b->prop = 'Prop data';
print_r($a);
/* Output
ArrayObject Object
(
[prop] => Prop data
[storage:ArrayObject:private] => Array
(
[arr] => Array data
)
)*/
print_r($b);
/* Output
ArrayObject Object
(
[storage:ArrayObject:private] => Array
(
[arr] => Array data
[prop] => Prop data
)
)*/
?>
If you need the last key of your collection use:
<?php
array_key_last($this->getArrayCopy())
?>
In an extending class it could look like:
<?php
class Collection extends ArrayObject
{
public function lastKey(): int
{
return array_key_last($this->getArrayCopy());
}
}
?>
If you want to use any type safe collection:
<?php
class BookCollection extends Collection
{
public function add(Book $book) : void
{
$this->offsetSet($book->id, $book);
}
// note the return type "Book"
public function get(int $bookId) : Book
{
$this->offsetGet($bookId);
}
}
?>
Note that this does not truly "allow objects to work as arrays" - an `ArrayObject` will not type-check as an array:
<?php
function gimme(array $a) {
var_dump($a);
}
$a = new ArrayObject([1,2,3]);
var_dump(is_array($a)); // false
gimme($a); // Uncaught TypeError: gimme(): Argument #1 ($a) must be of type array, ArrayObject given
?>
If you want something that type-checks both for arrays and `ArrayObject`, use the `iterable` pseudotype instead:
<?php
function gimme(iterable $a) {
var_dump($a);
}
$a = [1,2,3];
var_dump(is_iterable($a)); // true
var_dump($a instanceof iterable); // false (iterable is a pseudo-type and cannot be type-checked using instanceof)
gimme($a); // works
gimme(new ArrayObject($a)); // works
?>
Notice the caveat here, that arrays will not type-check as `instanceof iterable`, because pseudotypes cannot be checked that way - if you need a run-time type-check, use `is_iterable` for the type-check instead.