What’s new in PHP 7.4

PHP 7.4 was released on November 28, 2019 and it’s the last version before PHP 8.

New features

PHP 7.4 comes with a remarkable amount of new features.

The following a list of all new features.

Arrow functions, also called “short closures”, allow for less verbose one-liner functions.

// Previously
array_map(function (User $user) { 
    return $user->id; 
}, $users)

// Now
array_map(fn (User $user) => $user->id, $users)

// Previously

array_map(function (User $user) {

return $user->id;

}, $users)

// Now

array_map(fn (User $user) => $user->id, $users)

There are a few notes about arrow functions:

They can always access the parent scope, there’s no need for the use keyword.
$this is available just like normal closures.
Arrow functions may only contain one expression, which is also the return statement.

Class variables can be type hinted:

class TypedHintClass
{
    public string $name;
    
    public Foo $foo;
}

class TypedHintClass

{

public string $name;

public Foo $foo;

}

August 11, 2020