06c02-1.php

来自「介绍PHP5的给类型函数应用」· PHP 代码 · 共 21 行

<?php
// A function to add all the numbers from 1 to the number given.
// Excuted in this case, with a for loop
function sum_up_to($number) {
    $result = 0;
    for ($i = 1; $i <= $number; $i++) {
        $result += $i;
    }
    return $result;
}

// And now the same function, written as a recursive function
function sum_up_recursive($number) {
    return ($number) ? ($number + sum_up_recursive($number - 1)) : 0;
}

// Try this in both cases, with the number 42, which should return: 903
echo '<p>Regular version = ', sum_up_to(42), "</p>\n";
echo '<p>Recursive version = ', sum_up_recursive(42), "</p>\n";
?>