方法一：迭代器class myIterator implements Iterator {    private $position = 0;    private $current = 1;    private $previous = 0;    public function __construct(){}    public function rewind()    {        $this->position = 0;        $this->current = 1;        $this->previous = 0;    }    public function current()    {        return $this->current;    }    public function key()    {        return $this->position;    }    public function next()    {        $tem = $this->previous;        $this->previous = $this->current;        $this->current = $this->current + $tem;        ++$this->position;    }    public function valid()    {        return ($this->current !== false);    }} $it = new myIterator;foreach($it as $key => $value) {    // if ($key > 15) break;    echo "$value    ";}

方法二：生成器function generator(){    $current = 1;    $previous = 0;    while ($current) {        yield $current; // 重点在这里使用了yield        $temp = $current;        $current = $current + $previous;        $previous = $temp;    }}foreach (generator() as $key => $value) {    // if ($key > 15) break;    echo "$value    ";}