PHP 8 is now Released!

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The PHP development team announced that PHP version 8 has now been released:

PHP 8.0 is a major update of the PHP language.
It contains many new features and optimizations including named arguments, union types, attributes, constructor property promotion, match expression, nullsafe operator, JIT, and improvements in the type system, error handling, and consistency.

Here is the list of main new features:

  • Union Types
  • Named Arguments
  • Match Expressions
  • Attributes
  • Constructor Property Promotion
  • Nullsafe Operator
  • Weak Maps
  • Just In Time Compilation
  • And much much more…

Here are some of the highlights from the announcement:

Named arguments

  • Specify only required parameters, skipping optional ones.
  • Arguments are order-independent and self-documented.
//PHP 7
htmlspecialchars($string, ENT_COMPAT | ENT_HTML401, 'UTF-8', false);

//PHP 8
htmlspecialchars($string, double_encode: false);

Attributes

Instead of PHPDoc annotations, you can now use structured metadata with PHP’s native syntax.

//PHP 7

class PostsController
{
    /**
     * @Route("/api/posts/{id}", methods={"GET"})
     */
    public function get($id) { /* ... */ }
}

//PHP 8

class PostsController
{
    #[Route("/api/posts/{id}", methods: ["GET"])]
    public function get($id) { /* ... */ }
}

Constructor property promotion

Less boilerplate code to define and initialize properties.

//PHP 7

class Point {
  public float $x;
  public float $y;
  public float $z;

  public function __construct(
float $x 0.0,
float $y 0.0,
float $z 0.0,
  ) {
$this->$x;
$this->$y;
$this->$z;
  }
}

//PHP 8

class Point {
  public function __construct(
    public float $x 0.0,
    public float $y 0.0,
    public float $z 0.0,
  ) {}
}

Union types

Instead of PHPDoc annotations for a combination of types, you can use native union type declarations that are validated at runtime.

//PHP 7

class Number {
/** @var int|float */
private $number;

/**
   * @param float|int $number
   */
public function __construct($number) {
$this->number $number;
  }
}

new Number('NaN'); // Ok

//PHP 8

class Number {
  public function __construct(
    private int|float $number
) {}
}

new Number('NaN'); // TypeError

Match expression

The new match is similar to switch and has the following features:

  • Match is an expression, meaning its result can be stored in a variable or returned.
  • Match branches only support single-line expressions and do not need a break; statement.
  • Match does strict comparisons.
//PHP 7

switch (8.0) {
  case '8.0':
$result "Oh no!";
    break;
  case 8.0:
$result "This is what I expected";
    break;
}
echo $result;
//> Oh no!

//PHP 8

echo match (8.0) {
'8.0' => "Oh no!",
8.0 => "This is what I expected",
};
//> This is what I expected

Nullsafe operator

Instead of null check conditions, you can now use a chain of calls with the new nullsafe operator. When the evaluation of one element in the chain fails, the execution of the entire chain aborts and the entire chain evaluates to null.

//PHP 7

$country =  null;

if ($session !== null) {
$user $session->user;

  if ($user !== null) {
$address $user->getAddress();

    if ($address !== null) {
$country $address->country;
    }
  }
}

//PHP 8
$country $session?->user?->getAddress()?->country;
Saner string to number comparisons
When comparing to a numeric string, PHP 8 uses a number comparison. Otherwise, it converts the number to a string and uses a string comparison.
//PHP 7

== 'foobar' // true

//PHP 8

== 'foobar' // false
Consistent type errors for internal functions

Most of the internal functions now throw an Error exception if the validation of the parameters fails.

//PHP 7

strlen([]); // Warning: strlen() expects parameter 1 to be string, array given

array_chunk([], -1); // Warning: array_chunk(): Size parameter expected to be greater than 0

//PHP 8

strlen([]); // TypeError: strlen(): Argument #1 ($str) must be of type string, array given

array_chunk([], -1); // ValueError: array_chunk(): Argument #2 ($length) must be greater than 0

To checkout the detail official release please visit here.