Which is faster, regex or type casting, when deciding whether a string represents an integer?

is-integerstring-check-speed.php

<?php

$value = '0647№7№7№/0';


$time = microtime(true);
$loops = 100000;

$result = true;
for ($i = 0; $i < $loops; $i++) {
        $result &= preg_match('/^[0-9]+$/', $value);
}

echo "\nwith preg_match: " . (microtime(true) - $time);


$time = microtime(true);

$result = true;
for ($i = 0; $i < $loops; $i++) {
        $result &= ((string) (int) $value === $value);
}

echo "\nwith casting: " . (microtime(true) - $time);
echo "\n\n";

selbst für strings mit 1 char ist casting 3mal so schnell