Explore PHP7’s Powerful New Features: Types, Null Coalesce, Anonymous Classes & More

PHP 7, officially released in November 2015, marked a milestone for the language by delivering notable performance gains and a suite of new features.

Scalar Type Declarations

PHP 7 adds support for declaring scalar types (int, float, string, bool) for function parameters and return values, and introduces the declare(strict_types=1) directive to enforce strict type checking.

<code>function add(int $a, int $b): int {
    return $a + $b;
}
// With strict types enabled, passing a string will cause a TypeError.</code>

Null Coalescing Operator (??)

The null‑coalescing operator provides a concise way to retrieve a value or fall back to a default when the value is null or undefined.

<code><?php
// PHP 5 style
$username = isset($_GET['user']) ? $_GET['user'] : 'nobody';
// PHP 7 style
$username = $_GET['user'] ?? 'nobody';
?>
</code>

Anonymous Classes

Anonymous classes can be instantiated without a name, useful for one‑off objects.

<code>$obj = new class {
    public function myMethod() {
        return 'Hello';
    }
};
echo $obj->myMethod();
</code>

Improved Error Handling

Many engine errors are now represented as throwable Error objects, allowing them to be caught with try / catch blocks instead of causing fatal termination.

<code>try {
    nonExistFunction($arg);
} catch (Error $e) {
    // Handle the error and continue execution
}
</code>

Spaceship Operator (<=>)

The combined comparison operator returns -1, 0, or 1 when comparing two expressions, simplifying sorting logic.

<code>$result = $a <=> $b; // -1 if $a<$b, 0 if equal, 1 if $a>$b
</code>

Array Constants

PHP 7 allows defining constants that hold arrays using define() .

<code>define('MY_CONSTANT', ['a', 'b', 'c']);
</code>

These features collectively enhance code clarity, safety, and performance for modern PHP development.