strtr vs str_replace.php

<?php
// https://3v4l.org/gDRdq
$foo = 'a/b/c/d/e';
$bar = null;

$m = memory_get_usage();
$t = microtime(true);

for($i = 0; $i < 10000; $i++)
{
    $bar = strtr($foo, '/', '-');
}

var_dump(
    memory_get_usage() - $m, 
    microtime(true) - $t
);

echo $bar. "\n";

$bar = null;

$m = memory_get_usage();
$t = microtime(true);

for($i = 0; $i < 10000; $i++)
{
    $bar = str_replace('/', '-', $foo);
}

var_dump(
    memory_get_usage() - $m, 
    microtime(true) - $t
);

echo $bar. "\n";