Interface to detect if a class is traversable using foreach().
Abstract base interface that cannot be implemented alone. Instead it must be implemented by either IteratorAggregate or Iterator.
Note: Internal (built-in) classes that implement this interface can be used in a foreach() construct and do not need to implement IteratorAggregate or Iterator.
Note: This is an internal engine interface which cannot be implemented in PHP scripts. Either IteratorAggregate or Iterator must be used instead.
This interface has no methods, its only purpose is to be the base interface for all traversable classes.
Interface for external iterators or objects that can be iterated themselves internally.
Example #1 Basic usage
This example demonstrates in which order methods are called when foreach()ing over an iterator.
<?php
class myIterator implements Iterator {
private $position = 0;
private $array = array(
"firstelement",
"secondelement",
"lastelement",
);
public function __construct() {
$this->position = 0;
}
function rewind() {
var_dump(__METHOD__);
$this->position = 0;
}
function current() {
var_dump(__METHOD__);
return $this->array[$this->position];
}
function key() {
var_dump(__METHOD__);
return $this->position;
}
function next() {
var_dump(__METHOD__);
++$this->position;
}
function valid() {
var_dump(__METHOD__);
return isset($this->array[$this->position]);
}
}
$it = new myIterator;
foreach($it as $key => $value) {
var_dump($key, $value);
echo "\n";
}
?>
上例的输出类似于：
string(18) "myIterator::rewind" string(17) "myIterator::valid" string(19) "myIterator::current" string(15) "myIterator::key" int(0) string(12) "firstelement" string(16) "myIterator::next" string(17) "myIterator::valid" string(19) "myIterator::current" string(15) "myIterator::key" int(1) string(13) "secondelement" string(16) "myIterator::next" string(17) "myIterator::valid" string(19) "myIterator::current" string(15) "myIterator::key" int(2) string(11) "lastelement" string(16) "myIterator::next" string(17) "myIterator::valid"
Interface to create an external Iterator.
Example #1 Basic usage
<?php
class myData implements IteratorAggregate {
public $property1 = "Public property one";
public $property2 = "Public property two";
public $property3 = "Public property three";
public function __construct() {
$this->property4 = "last property";
}
public function getIterator() {
return new ArrayIterator($this);
}
}
$obj = new myData;
foreach($obj as $key => $value) {
var_dump($key, $value);
echo "\n";
}
?>
上例的输出类似于：
string(9) "property1" string(19) "Public property one" string(9) "property2" string(19) "Public property two" string(9) "property3" string(21) "Public property three" string(9) "property4" string(13) "last property"
Interface to provide accessing objects as arrays.
Example #1 Basic usage
<?php
class obj implements arrayaccess {
private $container = array();
public function __construct() {
$this->container = array(
"one" => 1,
"two" => 2,
"three" => 3,
);
}
public function offsetSet($offset, $value) {
$this->container[$offset] = $value;
}
public function offsetExists($offset) {
return isset($this->container[$offset]);
}
public function offsetUnset($offset) {
unset($this->container[$offset]);
}
public function offsetGet($offset) {
return isset($this->container[$offset]) ? $this->container[$offset] : null;
}
}
$obj = new obj;
var_dump(isset($obj["two"]));
var_dump($obj["two"]);
unset($obj["two"]);
var_dump(isset($obj["two"]));
$obj["two"] = "A value";
var_dump($obj["two"]);
?>
上例的输出类似于：
bool(true) int(2) bool(false) string(7) "A value"
Interface for customized serializing.
Classes that implement this interface no longer support __sleep() and __wakeup(). The method serialized is called whenever an instance needs to be serialized. This does not invoke __destruct() or has any other side effect unless programmed inside the method. When the data is unserialized the class is known and the appropriate unserialize() method is called as a constructor instead of calling __construct(). If you need to execute the standard constructor you may do so in the method
Example #1 Basic usage
<?php
class obj implements Serializable {
private $data;
public function __construct() {
$this->data = "My private data";
}
public function serialize() {
return serialize($this->data);
}
public function unserialize($data) {
$this->data = unserialize($data);
}
public function getData() {
return $this->data;
}
}
$obj = new obj;
$ser = serialize($obj);
$newobj = unserialize($ser);
var_dump($newobj->getData());
?>
上例的输出类似于：
string(15) "My private data"