phpMyAdmin: array search speed comparison

<?php
define('PHPMYADMIN', true);
require 'libraries/string.lib.php';
require 'libraries/sqlparser.data.php';


$iterations = 100000;
$word = 'WRITE';

$array_flipped = array_flip($PMA_SQPdata_forbidden_word);
$count = count($PMA_SQPdata_forbidden_word);

$t0 = microtime(true);
for ($i = 0; $i < $iterations; $i++) {
    PMA_STR_binarySearchInArr($word, $PMA_SQPdata_forbidden_word, $count);
}

$t1 = microtime(true);
for ($i = 0; $i < $iterations; $i++) {
    array_search($word, $PMA_SQPdata_forbidden_word);
}

$t2 = microtime(true);
for ($i = 0; $i < $iterations; $i++) {
    isset($array_flipped[$word]);
}

$t3 = microtime(true);
for ($i = 0; $i < $iterations; $i++) {
    array_key_exists($word, $array_flipped);
}

$t4 = microtime(true);
for ($i = 0; $i < $iterations; $i++);
$t5 = microtime(true);
$loop_overhead = $t5 - $t4;
?>
<pre style="white-space:pre-wrap;">
Binary search:    <?php echo round($t1-$t0-$loop_overhead, 4) . "\n"; ?>
array_search:     <?php echo round($t2-$t1-$loop_overhead, 4) . "\n"; ?>
isset:            <?php echo round($t3-$t2-$loop_overhead, 4) . "\n"; ?>
array_key_exists: <?php echo round($t4-$t3-$loop_overhead, 4) . "\n"; ?>
</pre>