This post serves as a reminder, it is so easy to forget things nowadays. So here you go all in one list of PHP 7+ new features.

Beware though, it is not 100% full, but 85-90% I think, I did omit some not-so-important features. I would be so glad if this article helped to save your time.

Changes introduced in 7.0

Scalar type declarations
An option to make PHP more stict on typing. We have the following types:

  • int
  • float
  • string
  • bool

Return type declarations
Up to PHP7.1 the types are:

  • class
  • interface
  • self
  • array
  • callable
  • bool
  • float
  • int
  • stiring
  • iterable

Null coalescing operator
It is an eleagant way to get rid of isset():

$test = $_POST['surprise'] ?? 'nothing';

So in case post variable does not exists or it is null, we’ll get the value after ??

Spaceship operator

echo $x <=> $b;

Will return 0 in case variables are equal, -1 if $b is more\equal to the be and 1 if vise versa.

Anonymous classes:

new class extends SomeOtherClass
{}

So yeah, it’s an old plain class which can extend, implement and etc.

Unicode codepoint escape syntax

echo "\u{6879}";

Will output 桹

Closure::call
Shorthand way to get everything you need from the class.
Could we say we do not need Reflection any more ?

class A {private $x = 42;} 
print (function(){ return $this->x;})->call(new A);

Filtered unserialize function
Now unserialize have an optional option allowed_classes for better security:

unserialize($some_string, ['allowed_classes' => ['MyA', 'MyB']]);

Interestingly enough, in case we pass some other class we will get instance of __PHP_Incomplete_Class

IntlChar
Intl extension received new class IntlChar, it holds a number of useful method to work with unicode characters.
For instance charAge which lets you have a Unicode version when this character was introduced, or charName which well, lets you get char name and etc.

Expectation
It is assert enhancement, previously you could use it like this:

var_dump(assert('true !== false'));

which would be validated to true or false roughly speaking. But in PHP7 assert() is a language construct so the first parameter - assertion can be an expression and the second parameter can be now of type throwable so we can throw Exception.

Group use declaration
We can them like this:

use some\namespace\{ClassA, ClassB, ClassC as C};

Though it kind of contradicts with PSR-4 which does not allow grouping.

Generator return expressions
With new Generator function getReturn() we may retrieve the final expression like this:

$gen = (function(){
    yield 1;
    return 'The end' . PHP_EOL;
})();

Only when generator is done yielding values, we can use $gen->getReturn() and see the final result. Pretty handy!

Generator delegation
The generator can do yield from and suck in other generator, array or any Traversable object.

Things deprecated:
{: style=“color:red;” }

  • PHP 4 style constructors
  • Static calls to non-static methods
  • calling assert() with string argument
  • password_hash() salt option

Changes introduced in 7.1

Nullable types
Nullable type means that along with specified type we can pass or return NULL.
Here is quite silly but legit example.

function a(?string $line): ?string
{
    return $line;
}

Void functions
New return type void that is used in case we omit return or we do return;

Symmetric array destructuring
Means that now along with classical list() we can do this:

$data = ['blah', 'ping-pong'];
[$first, $second] = $data;

$first will be created and equal to ‘blah’ and $second will be equal to’ping-pong’, hence the name - symmetric array destructturing : )

Class constant visibility
Well, constants can now be private, protected and public

iterable pseudo-type
New return type, similar to callable() - iterable
Of course it can be user for array or object implemeting Traversable interface

Multi catch exception handling
Catch block may now have multiple exceptions specified with pipe | character like this

...
} catch( LigicException | RuntimeException $e) {
...

Support for keys in list() or in [] array desctucuring
list and symmetric array destructuring support keys, so we can do it like this:

$data = [
    ["id" => 1, "name" => 'Tom'],
    ["id" => 2, "name" => 'Fred'],
];

list("name" => $name, "id" => $id) = $data[0];

["name" => $name, "id" => $id] = $data[0];

Support for negative string offsets
With negative offset we can do var_dump("testy"[-1]); and receive y letter.
Also all string manipulation function are able to use negative offset as well.

Convert callables to Closures with Closure::fromCallable()

Asynchronous signal handling

HTTP/2 server push support in ext/curl

Things deprecated:
{: style=“color:red;” }

  • extension ext/mcrypt
  • the e pattern modifier is deprecated for the mb_ereg_replace() and mb_eregi_replace() functions.

Changes introduced in 7.2

New object type
It can be used as type hint and as return type as well:

function(object $obj): object {
    return new SplFileInfo();
}

Extension loading by name
No need to write extension name along with file extension, .so in Unix case.

Abstract method override
Now we are able to create child abstact class and override parent’s abstract methods:

abstract class A
{
    abstract function test(string $s);
}
abstract class B extends A
{
    abstract function test($s) : int;
}

password_hash will support Argon2 hashing algorithm
All password_...functions have a bunch of ARGON2 constants available to them.

New cryptographic extension - Sodium

object as type hint and return type

Parameter Type Widening

interface A
{
        public function Test(array $input);
}

class B implements A
{
        public function Test($input){}
}

Trailing comma is alowed in grouped namespaces

Things deprecated:
{: style=“color:red;” }

  • unquoted strings in php7.2+ will emir E_WARNING instead of E_NOTICE
  • __autload() deprecated in favor of superior spl_autoload_register()
  • useless (unset) cast
  • create_function()
  • using parse_str() function without second argument
  • each() function due to slowness
  • assert() with string argument

Changes introduced in 7.3

▪ JSON throw on error
As fourth parameter json_decode() and json_encode functions receive bitmask of JSON decode options.
JSON_THROW_ON_ERROR will be added to these options, it wont change behavior of json_last_error() and json_last_error_msg(). With that additional option json_decode() and json_encode functions will throw JsonException.

Things deprecated:
{: style=“color:red;” }

  • not yet