To implement a Fibonacci sequence with a PHP iterator

The Fibonacci sequence is usually done recursively, and of course there are other methods. Now learn to sell, use PHP iterator to implement a Fibonacci sequence, almost no difficulty, but the class of the next () method rewrite once. Comments have been written into the code and are fairly well understood.

Current

}

Public Function key () {

return $this->key;

}

Public function next () {

The key is here.

Saves the current value to the $newprevious

$newprevious = $this->current;

Assigns the previous value and the current value to the current value

$this->current + + $this->previous;

Previous value assigned to last

$this->previous = $newprevious;

$this->key++;

}

Public Function Rewind () {

$this->previous = 1;

$this->current = 0;

$this->key = 0;

}

Public Function valid () {

return true;

}

}

$seq = new Fibonacci;

$i = 0;

foreach ($seq as $f) {

echo "$f";

if ($i + + = =) break;

}

?>

Program Run Result:

0 1 1 2 3 5 8 13 21 34 55 89 144 233-377 610