PHP - Generate Fibonacci Series #loop #foreach

generateFibonacciSeries.php

<?php
//version 1
function generateFibonacciSeries($input) {
       $range = range(0,$input);
       $output = [];

       foreach($range as $number) {
              if($number == 0 || $number == 1) {
                     array_push($output, $number);
              } elseif (array_key_exists($number+1, $range)) {
                     $fbchiNumber = $output[$number-1] + $output[$number-2];
                     array_push($output, $fbchiNumber);
              }
       }
       //[0,1,1,2,3,5,8,13,21....]
       return $output;
}

//version 2
function generateFibonacciSeries($input) {
       $range = range(0,$input-1);
       $output = [0,1];

       foreach($range as $key) {
              if($key == 0 || $key == 1) {
                     continue;
              } else {
                     $fbchiNumber = $output[$key-1] + $output[$key-2];
                     array_push($output, $fbchiNumber);
              }
       }
       //[0,1,1,2,3,5,8,13,21....]
       return $output;
}

//version 3
function generateFibonacciSeries($input) {
       $range = range(1,$input);
       $output = [0,1];
       $ignore = [0,1,count($range)];

       foreach($range as $key) {
              if(!in_array($key, $ignore)) {
                     array_push(
                            $output, 
                            $output[$key-1] + $output[$key-2]
                     );
              }
       }
       //[0,1,1,2,3,5,8,13,21....]
       return $output;
}

//Call it
echo "<pre>";
print_r(generateFibonacciSeries(9));
echo "</pre>";

generateFibonacciSeriesRecursive.php

<?php

$fiboData = [];
$number = (int)'9';
/**
 * generate Fibonacci series
 *
 * @param int $number
 * @param int $prev 
 * @param int $cur
 * @param array $fiboData
 * @return void
 */
function generateFibonacci($number, &$fiboData, $prev = 0, $cur = 1) {
	//transform to positive
	if ($number < 0) $number = -$number;

	if ($prev == 0) {
		$fiboData[] = $prev;
	}

	$fiboData[] = $cur;
	$data = $prev + $cur;

    if ($number <= 2) return;

    generateFibonacci($number-1, $fiboData, $cur, $data);
}

generateFibonacci($number, $fiboData);

echo '<pre>';
print_r($fiboData);
echo '</pre>';

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