Source code in the powershell programming language

function FibonacciNumber ( $count )
{
    $answer = @(0,1)
    while ($answer.Length -le $count)
    {
        $answer += $answer[-1] + $answer[-2]
    }
    return $answer
}

$count = 8
$answer = @(0,1)
0..($count - $answer.Length) | Foreach { $answer += $answer[-1] + $answer[-2] }
$answer

function fib($n) {
    switch ($n) {
        0            { return 0 }
        1            { return 1 }
        { $_ -lt 0 } { return [Math]::Pow(-1, -$n + 1) * (fib (-$n)) }
        default      { return (fib ($n - 1)) + (fib ($n - 2)) }
    }
}