Benchmarking "(array) $var === $var" vs "is_array($var)" for speed

is_array_benchmark.php

<?php

/**
 * @param array $functions  An associative array of closures to benchmark
 * @param int   $iterations The number of iterations
 */
function benchmark($functions, $iterations)
{
    foreach ($functions as $name => $function) {
        $start = microtime(true);

        for ($i = 0; $i < $iterations; $i++) {
            call_user_func($function);
        }

        $delta = microtime(true) - $start;

        echo "$name: " . $delta . "\n";
    }
}


$data = array(
    'string',                       // Not an array
    array(1, 2, 3),                 // Small array
    array_fill(1, 10000, uniqid())  // Large-ish array
);

$functions = array(
    'casting' => function () use ($data) {
        foreach ($data as $d) {
            $result = (array) $d === $d;
        }
    },
    'is_array' => function () use ($data) {
        foreach ($data as $d) {
            $result = is_array($d);
        }
    }
);


echo "Benchmarking \"(array) \$var === \$var\" vs \"is_array(\$var)\" ...\n";

benchmark($functions, 10000);

Results on an iMac 2.7 GHz Intel Core i5 with 12GB RAM with PHP 5.4 (less is better)

casting: 6.4870979785919
is_array: 0.010051012039185

Using the same benchmark function, comparing count($array) == 0 vs empty($array) (less is better)

count(): 4.2716100215912
empty(): 3.3020689487457

<?php

// ...

echo "\nBenchmarking \"count(\$var) == 0\" vs \"empty(\$var)\" ...\n";

$data = range(1, 1000000);

benchmark(array(
    'count()' => function () use ($data) {
        $result = count($data) == 0;
    },
    'empty()' => function () use ($data) {
        $result = empty($data);
    }
), 10000000);

in_array_keys($key, $array) vs $array[$key] (less is better)

in_array_keys(): 4.8499279022217
key check: 3.8257780075073

<?php

// ...

echo "\nBenchmarking \"array_key_exists(\$key, \$array)\" vs \"\$array[\$key]\" ...\n";

$data = array_fill_keys(range(1, 1000), uniqid());

benchmark(array(
    'in_array_keys()' => function () use ($data) {
        $result = array_key_exists(50, $data) ? : null;
    },
    'key check' => function () use ($data) {
        $result = $data[50] ? : null;
    }
), 10000000);