ArtisanTinkerer.github.io by ArtisanTinkerer

https://github.com/smknstd/modern-php-cheatsheet

Type declaration

function myFunction(int $param)

Return types

function myFunction() : int

When a function should not return anything:

function myFunction() : void

Class property

Class Foo()
{
    public int $bar;
}

Union types

function myFunction(string|int|array $param) : string|int|array

Nullable types

If no type it can accept a null

function myFunction($param)

but as soon as it has a type it won’t take a null.

You can make a type declaration explicitly nullable:

function myFunction(?string $param)

and return types:

function myFunction(?string $param) : ?string

Destructuring arrays

list($a, $b, $c) = $array;
#assocs
list('foo' => $a, 'bar' => $b, 'baz' => $c) = $array;

Null Coalescing

Fall back when nullable - or undefined

$b = $a ?? 'fallback';

# can chain
$c = $a ?? $b ?? 'fallback';


# and an assoc if that element is missing
$b = $a['foo'] ?? 'fallback';

# Null coalescing on object
# property cannot be found

$b = $a->baz ?? 'fallback';

# Or a method - which returns null
$b = $a->bar() ?? 'fallback';
# but error if method not found

Nullsafe operator

$a = null;
$b = $a?->foo;

Spread operator

function countParameters(string $param, string ...$options) : int

Argument unpacking

function add(int $a, int $b, int $c) : int
{
    return $a + $b + $c;
}
$array = [2, 3];
$r = add(1, ...$array);

Array unpacking

$array1 = ['foo', 'bar'];
$array2 = ['baz', ...$array1];