Compare string concatenation speed to array imploding, when it comes to combining strings

concatenation_benchmark.php

<?php

/**
 * I was explaining how strings and arrays are stored differently in RAM to my
 * students and I told them, that array imploding is much more efficient than
 * traditional string concatenation.
 *
 * I created this benchmark to prove my point.
 */

$iterations = 100000;
$test_string = 'foobar';

function echo_n ($str, $n_and_r = false) {
    if ($n_and_r === true) {
        echo "<p>{$str}</p>";
    } else {
        echo "{$str}<br>";
    }
}

echo_n("Starting Benchmark with $iterations iterations", true);

// string concat
$start = microtime(true);
echo_n("Start: $start (concat)");

$string = '';
for ($i = 0; $i <= $iterations; $i++) {
    if ($i > 0) {
        $string .= " $test_string";
    } else {
        $string .= "$test_string";
    }
}

$end = microtime(true);
$duration1 = $end - $start;
echo_n("End: $end");
echo_n("Duration: $duration1 milliseconds");

// array implode
echo_n("");
$start = microtime(true);
echo_n("Start: $start (array)");

$array = [];
for ($i = 0; $i <= $iterations; $i++) {
    $array[] = $test_string;
}
$string2 = implode(' ', $array);


$end = microtime(true);
$duration2 = $end - $start;
echo_n("End: $end");
echo_n("Duration: $duration2 milliseconds");

// Do both methods produce the same result?
if ($string === $string2) {
    echo_n("Both generated strings are the same! Yay! :D", true);
}

// Results
if ($duration1 < $duration2) {
    $factor = round($duration2 / $duration1, 1);
    echo_n("The winner is string concatenation, with a duraction of $duration1 over $duration2, that equals a factor of $factor", true);
} elseif ($duration1 > $duration2) {
    $factor = round($duration1 / $duration2, 1);
    echo_n("The winner is array imploding, with a duraction of $duration2 over $duration1, that equals a factor of $factor", true);
} else {
    echo_n("We have no winner, both methods are equal.", true);
}

?>