锟斤拷锟斤拷锟斤拷锟斤拷

PHP 5 锟结供锟斤拷一锟街讹拷锟斤拷锟斤拷锟侥凤拷锟斤拷使锟斤拷锟斤拷锟酵拷锟斤拷锟皆拷斜锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟� foreach 锟斤拷洹Ｄ拷锟斤拷锟斤拷锟铰ｏ拷锟斤拷锟斤拷锟缴硷拷锟斤拷锟皆讹拷锟斤拷锟斤拷锟斤拷锟节憋拷锟斤拷锟斤拷

Example #1 锟津单的讹拷锟斤拷锟斤拷锟�


<?php
class MyClass
{
    public $var1 = 'value 1';
    public $var2 = 'value 2';
    public $var3 = 'value 3';

    protected $protected = 'protected var';
    private   $private   = 'private var';

    function iterateVisible() {
       echo "MyClass::iterateVisible:\n";
       foreach($this as $key => $value) {
           print "$key => $value\n";
       }
    }
}

$class = new MyClass();

foreach($class as $key => $value) {
    print "$key => $value\n";
}
echo "\n";


$class->iterateVisible();

?>

锟斤拷锟斤拷锟斤拷锟教伙拷锟斤拷锟斤拷锟�

var1 => value 1
var2 => value 2
var3 => value 3

MyClass::iterateVisible:
var1 => value 1
var2 => value 2
var3 => value 3
protected => protected var
private => private var

锟斤拷锟斤拷锟斤拷示锟斤拷foreach 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟杰癸拷锟斤拷锟绞碉拷锟缴硷拷锟斤拷锟皆★拷

锟斤拷锟斤拷一锟斤拷锟斤拷锟斤拷锟斤拷实锟斤拷 Iterator 锟接匡拷锟斤拷锟斤拷锟斤拷锟矫讹拷锟斤拷锟斤拷锟叫撅拷锟斤拷锟斤拷伪锟斤拷锟斤拷约锟矫匡拷伪锟斤拷锟绞憋拷锟叫┲碉拷锟斤拷谩锟�

Example #2 实锟斤拷 Iterator 锟接口的讹拷锟斤拷锟斤拷锟�


<?php
class MyIterator implements Iterator
{
    private $var = array();

    public function __construct($array)
    {
        if (is_array($array)) {
            $this->var = $array;
        }
    }

    public function rewind() {
        echo "rewinding\n";
        reset($this->var);
    }

    public function current() {
        $var = current($this->var);
        echo "current: $var\n";
        return $var;
    }

    public function key() {
        $var = key($this->var);
        echo "key: $var\n";
        return $var;
    }

    public function next() {
        $var = next($this->var);
        echo "next: $var\n";
        return $var;
    }

    public function valid() {
        $var = $this->current() !== false;
        echo "valid: {$var}\n";
        return $var;
    }
}

$values = array(1,2,3);
$it = new MyIterator($values);

foreach ($it as $a => $b) {
    print "$a: $b\n";
}
?>

锟斤拷锟斤拷锟斤拷锟教伙拷锟斤拷锟斤拷锟�

rewinding
current: 1
valid: 1
current: 1
key: 0
0: 1
next: 2
current: 2
valid: 1
current: 2
key: 1
1: 2
next: 3
current: 3
valid: 1
current: 3
key: 2
2: 3
next:
current:
valid:

锟斤拷锟斤拷锟斤拷 IteratorAggregate 锟接匡拷锟斤拷锟斤拷锟绞碉拷锟斤拷锟斤拷械锟� Iterator 锟斤拷锟斤拷锟斤拷IteratorAggregate 只锟斤拷要实锟斤拷一锟斤拷锟斤拷锟斤拷 IteratorAggregate::getIterator()锟斤拷锟斤拷应锟斤拷锟斤拷一锟斤拷实锟斤拷锟斤拷 Iterator 锟斤拷锟斤拷锟绞碉拷锟斤拷锟�

Example #3 通锟斤拷实锟斤拷 IteratorAggregate 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷


<?php
class MyCollection implements IteratorAggregate
{
    private $items = array();
    private $count = 0;

    // Required definition of interface IteratorAggregate
    public function getIterator() {
        return new MyIterator($this->items);
    }

    public function add($value) {
        $this->items[$this->count++] = $value;
    }
}

$coll = new MyCollection();
$coll->add('value 1');
$coll->add('value 2');
$coll->add('value 3');

foreach ($coll as $key => $val) {
    echo "key/value: [$key -> $val]\n\n";
}
?>

锟斤拷锟斤拷锟斤拷锟教伙拷锟斤拷锟斤拷锟�

rewinding
current: value 1
valid: 1
current: value 1
key: 0
key/value: [0 -> value 1]

next: value 2
current: value 2
valid: 1
current: value 2
key: 1
key/value: [1 -> value 2]

next: value 3
current: value 3
valid: 1
current: value 3
key: 2
key/value: [2 -> value 3]

next:
current:
valid:

Note:
锟斤拷锟斤拷锟斤拷锟斤拷锟绞撅拷锟斤拷锟� SPL 锟斤拷展锟斤拷

Note:
PHP 5.5 锟斤拷锟皆猴拷姹撅拷锟斤拷没锟揭诧拷刹慰锟�锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟结供锟斤拷锟斤拷一锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷 Iterators锟斤拷