Question

请问高手，这段PHP对象迭代程序的执行顺序是什么，并帮解释一下结果？

<?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";
}
?>

运行结果：
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:
请详细解释一下这个结果。

Answer 1

。。。。。这不是PHP手册里面的一段代码嘛，看手册去

追问

能看懂就不问了