<?php
$foo = 42;
$bar = 64;
$start = microtime(true);
for ($i = 0; $i <= 1000; $i++) {
"$foo $bar";
}
echo microtime(true) - $start;
echo "\n";
$start = microtime(true);
for ($i = 0; $i <= 1000; $i++) {
$foo . ' ' . $bar;
}
echo microtime(true) - $start;
echo "\n";