Binary Search in PHP using recursion

binary-search.php

#!/usr/bin/php
<?php

/*
 * Binary Search Function - uses recursion
 *
 */
function binarySearch(array $search, int $find): bool
{
    $length = count($search);

    // base condition. make it stop if necessary.
    if ($length === 0) {
        return false;
    }

    $mid_index = floor($length / 2);
    $mid_value = $search[$mid_index];

    if ($find === $mid_value) {
        echo "FOUND IT! mid_value={$mid_value}\n";
        return true;
    }

    // Default to the lower half
    $low = 0;
    $high = $mid_index;
    if ($find > $mid_value) {
        // Just kidding! it's in the upper half
        $low = $mid_index + 1;
        $high = $length;
    }

    $sub_length = $high - $low;
    $new_search = array_slice($search, $low, $sub_length);

    return binarySearch($new_search, $find);
}

// ------------------------------------------
// Test code
// ------------------------------------------
$search = [0, 1, 3, 5, 6, 7, 12, 23, 34, 88, 92, 96, 100];
$result = binarySearch($search, 3) ? "Found" : "Not Found";

echo "
-----------------------------
Result: $result
-----------------------------
\n";