« back — written by Brent on July 16, 2021

PHP 8.1: before and after

The release of PHP 8.1 will be here within a few months, and once again there are many features that get me excited! In this post I want to share the real-life impact that PHP 8.1 will have on my own code.

# Enums

A long-awaited feature, enums are coming! There's little to be said about this one, besides that I'm looking forward to not having to use spatie/enum or myclabs/php-enum anymore. Thanks for all the years of enum support to those packages, but they are the first I'll ditch when PHP 8.1 arrives and when I change this:

/**
 * @method static self draft()
 * @method static self published()
 * @method static self archived()
 */
class StatusEnum extends Enum
{
}

PHP 8.0

To this:

enum Status
{
    case draft;
    case published;
    case archived;
}

PHP 8.1

# Array unpacking with string keys

This one might seem like a small one, but it has bothered me more than once: only list arrays could be unpacked before PHP 8.1:

$a = [1, 2, 3];
$b = [4, 5, 6];

// This is allowed
$new = [...$a, ...$b];

PHP 8.0

While arrays with string keys cannot:

$a = ['a' => 1, 'b' => 2, 'c' => 3];
$b = ['d' => 4, 'e' => 5, 'f' => 6];

$new = [...$a, ...$b]; 

// You'd need to use array_merge in this case
$new = array_merge($a, $b); 

PHP 8.0

And so, one of the great features of PHP 8.1 that will make my life easier, is that arrays with string keys can now be unpacked as well!

$a = ['a' => 1, 'b' => 2, 'c' => 3];
$b = ['d' => 4, 'e' => 5, 'f' => 6];

// :)
$new = [...$a, ...$b]; 

PHP 8.1

# Class properties: initializers and readonly

Another stunning new feature is once again such a quality-of-life improvement that I've struggled with for years: default arguments in function parameters. Imagine you'd want to set a default state class for a BlogData object. Before PHP 8.1 you'd have to make it nullable and set it in the constructor:

class BlogData
{
    public function __construct(
        public string $title,
        public ?BlogState $state = null,
    ) {
        $this->state ??= new Draft();
    }
}

PHP 8.0

PHP 8.1 allows that new call directly in the function definition. This will be huge:

class BlogData
{
    public function __construct(
        public string $title,
        public BlogState $state = new Draft(),
    ) {
    }
}

PHP 8.1

Speaking of huge, have I mentioned yet that readonly properties are a thing now?!?

class BlogData
{
    public function __construct(
        public readonly string $title,
        public readonly BlogState $state = new Draft(),
    ) {
    }
}

PHP 8.1

Oh and don't worry about cloning, by the way: I've got you covered.

# First-class callable syntax

As if that wasn't enough, there's now also the first-class callable syntax, which gives you a clean way of creating closures from callables.

Previously you'd had to write something like this:

$strlen = Closure::fromCallable('strlen');
$callback = Closure::fromCallable([$object, 'method']);

PHP 8.0

In PHP 8.1, you can do… this:

$strlen = strlen(...);
$callback = $object->method(...);

PHP 8.1

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There are even more features in PHP 8.1, but these are the ones I'm most exited about. What's your favourite one? Let me know on Twitter!

Footnotes

Enums in PHP 8.1

Cloning readonly properties in PHP 8.1

What's new in PHP 8.1

PHP 8: before and after