assert-test.php

<?php

class FooBar { }

$fooBar = new FooBar();

$iterations = 1e6;

$assignment = false;
$start = microtime(true);
for ($i=0; $i<$iterations; $i++) {
	if ($fooBar instanceof FooBar) {
		$assignment = true;
	}
}

$instanceOnly = microtime(true) - $start;
fprintf(STDERR, "instance only: %2.2f\n", $instanceOnly);

$assignment = false;
$start = microtime(true);
for ($i=0; $i<$iterations; $i++) {
	assert($fooBar instanceof FooBar);
	$assignment = true;
}

$assert = microtime(true) - $start;
fprintf(STDERR, "assert: %2.2f\n", $assert);

fprintf(STDERR, "assert adds %2.6f ms overhead per invocation\n", ( ($assert - $instanceOnly) / $iterations ) * 1000);