There's a lot PHP 7 love going around these days, but PHP 5.6 has it's fair share of nice features too. One of those features is the splat operator. It looks like this: ....

The splat operator can capture a variable number of arguments.

function logThis(...$messages)
{
    foreach ($messages as $message) {
        echo $message.PHP_EOL;
    }
}

logThis('one', 'two', 'three');

You can still use regular arguments as well:

function logThis($firstMessage, ...$otherMessages)
{
    echo "superimportant: {$firstMessage}".PHP_EOL;

    foreach ($otherMessages as $message) {
        echo $message.PHP_EOL;
    }
}

logThis('one', 'two', 'three');

Another usage for the splat operator is argument unpacking:

$messages[] = "one";
$messages[] = "two";
$messages[] = "three";

logThis(...$messages);

The operator can also help replacing usages of call_user_func_array to something more readable. Consider this contrived example where all calls to a class are forwarded to a dependency.

class ClassA
{
    protected $classB;

    public function __construct(ClassB $classB)
    {
        $this->classB = $classB;
    }

    public function __call($method, $args)
    {
        call_user_func_array([$this->classB, $method], $args);
    }
}

Using this splat operator this can be rewritten to:

class ClassA
{
    protected $classB;

    public function __construct(ClassB $classB)
    {
        $this->classB = $classB;
    }

    public function __call($method, $args)
    {
        $this->classB->$method(...$args);
    }
}

Do you know some other cool usage of the operator? Let me know in the comments below.