function fib($n)
{
$cur = 1;
$prev = 0;
for ($i = 0; $i < $n; $i++) {
yield $cur; $temp = $cur;
$cur = $prev + $cur;
$prev = $temp;
}
} $fibs = fib(9);
foreach ($fibs as $fib) {
echo " " . $fib;
} // output: 1 1 2 3 5 8 13 21 34