PHP 7.0: Speed and Type Declarations in the Long-Awaited Release

PHP 7.0 was officially released this week. It’s the biggest version jump since PHP 5.0. It had been talked about for years — in community polls, at conferences, on developer blogs. I’ve spent the last few days reading about it and running tests, so I wanted to share my first impressions.

A quick caveat: this post is not a deep-dive guide to PHP 7.0. The release just dropped this week and I haven’t used it in a production project yet. But the standout changes are noteworthy enough to write about.

Performance gains

The most talked-about feature in PHP 7.0 isn’t a language feature — it’s the engine. Zend Engine 3 (the core of PHP) has been rewritten. The benchmarks on PHP.net show up to twice the speed compared to PHP 5.6 on real-world applications. Tests against popular apps like WordPress, Drupal, and Magento show significant improvement as well.

A leap that large doesn’t come from a language feature alone — it comes from optimizations at the engine level. Memory usage is down too. I haven’t felt the full practical impact beyond test environments yet, but the numbers are impressive.

Scalar type declarations

In PHP 5.x, type declarations in function signatures were only possible for classes, interfaces, and array. Primitive (scalar) types like int, float, string, and bool were not supported.

PHP 7.0 changes that:

function topla(int $a, int $b): int
{
    return $a + $b;
}

echo topla(3, 4);   // 7
echo topla(3.7, 4); // 7 — PHP coerces 3.7 to 3

The default behavior is coercive mode — PHP attempts to convert the value where possible. To enable strict mode, add this at the top of your file:

declare(strict_types=1);

In strict mode, calling topla(3.7, 4) throws a TypeError. Which mode you use depends on your needs, but strict mode makes intent far more explicit.

Return type declarations

It’s not just parameters — return types can be declared on functions too:

function bolKelimeler(string $cumle): array
{
    return explode(' ', $cumle);
}

function tamSayi(float $sayi): int
{
    return (int) $sayi;
}

The void return type isn’t in PHP 7.0 yet (it’s coming in 7.1), but int, float, string, bool, array, callable, and class names are all supported. This makes function contracts much more readable — you can tell what a function returns just from its signature, without reading the body.

Combined comparison operator: <=>

Also known as the “spaceship operator.” It compares two values and returns -1, 0, or 1:

echo 1 <=> 2;  // -1 (left is smaller)
echo 2 <=> 2;  //  0 (equal)
echo 3 <=> 2;  //  1 (left is larger)

It’s particularly handy when writing sort callbacks for functions like usort():

usort($kullanicilar, function ($a, $b) {
    return $a->yas <=> $b->yas;
});

Previously you’d write if ($a > $b) return 1; elseif ($a < $b) return -1; return 0;.

Null coalescing operator: ??

Shorthand for an isset() check combined with a default value:

// Old way
$isim = isset($_GET['isim']) ? $_GET['isim'] : 'Misafir';

// PHP 7.0
$isim = $_GET['isim'] ?? 'Misafir';

Multiple nulls can be chained:

$deger = $a ?? $b ?? $c ?? 'varsayilan';

Anonymous classes

PHP 7.0 introduces anonymous class support. Instead of defining a full class just to create a one-off object:

$logger = new class {
    public function log(string $mesaj): void
    {
        echo date('H:i:s') . ' — ' . $mesaj . PHP_EOL;
    }
};

$logger->log('Bir şey oldu.');

Creating objects without naming a class is useful when writing tests or for short-lived usage patterns.

What now?

PHP 7.0 just came out; it makes sense to wait a few months before moving production workloads over. You’ll want to audit your dependencies for compatibility and confirm framework support. Laravel 5.1 and Symfony 3.0 have been prepared for PHP 7.0 support.

But there’s no reason not to set it up in a test environment and start experimenting. Scalar type declarations and the performance improvements signal that PHP is maturing into a more serious platform. These are steps the community has been waiting a long time to see.