foreach vs array_walk

speed_test.php

<?php

$testBase = array_fill(0, 100000, 'testdata');
echo "Test array count: " . count($testBase) . PHP_EOL;

for($x = 0; $x < 10; $x++ ) {
    echo "Test #$x" . PHP_EOL;


    /* foreach test */
    $testCopy = array();
    $before = microtime(true);
    foreach ($testBase as $key => $value) {
        $testCopy[$key] = $value . 'asdasd';
    }
    $after = microtime(true);
    $dif = $after - $before;
    echo "foreach test ($before, $after): $dif" . PHP_EOL;

    /* array_walk test */
    $testCopy = $testBase;
    $before2 = microtime(true);
    array_walk($testCopy, function(&$value, $key) {
        $value = $value . 'qweqwe';
    });
    $after2 = microtime(true);
    $dif2 = $after2 - $before2;
    echo "array_walk test ($before2, $after2): $dif2" . PHP_EOL;
}