php fibonacci

fibonacci.php

<?php
/**
 * Get value of index in fibonacci series
 *
 * @author Ali OYGUR <alioygur@gmail.com>
 * @param  int $n index number
 * @return int    value of index
 */
function fibonacci($n)
{
	// 0,1
	$fib = array(0,1);
	// 1,1
	//$fib = array(1,1);
	
	for($i = 1; $i < $n; $i++) {
		$fib[] = array_sum($fib);
		$fib   = array_slice($fib, 1, NULL, TRUE);
	}
	return $fib[$n];
}

/**
 * Get fibonacci series
 *
 * @author Ali OYGUR <alioygur@gmail.com>
 * @param  int $n series length
 * @return array  the fibonacci series
 */
function fibonacci_series($n)
{	
	// use 0,1 series
	$fib = array(0,1);
	// OR you can use 1,1 series
	//$fib = array(1,1);
	
	for($i = 1; $i < $n; $i++) {
		$fib[] = array_sum(array_slice($fib, -2));
	}

	return $fib;
}
// End of file