Three functions that compute the sum of the numbers in a given list using a for-loop, a while-loop, and recursion using PHP

index.php

<?php

function one($a) {
	$count = count($a);
	$total = 0;
	for ($i=0; $i < $count; $i++) { 
		$total = $total + $a[$i];
	}
	echo $total;
}

function two($b) {
	$count = count($b);
	$start = 0;
	$total = 0;
	while ($start < $count) {
		$total = $total + $b[$start];
		$start++;
	}
	echo $total;
}

function three($c) {
	if(count($c) == 1) {
		return $c[0];
	}
	else {
		return array_shift($c) + three($c);
	}
}

// $list = 174
$list = array(5, 10, 1, 89, 4, 65 );
one($list);
echo "<br>";
two($list);
echo "<br>";
echo three($list);
?>

From here (https://blog.svpino.com/2015/05/07/five-programming-problems-every-software-engineer-should-be-able-to-solve-in-less-than-1-hour)