PHP 8.0, 8.1, 8.2, 8.3… what’s new?! CheatSheet.

The idea of this note is to write down PHP 8+ what’s news briefly, so they are visible all at once on a single page. Like a cheat-sheet.

Keep in mind that these are just the basic features, see each version’s link for more details.

PHP 8.0 What’s new

Named function arguments (i.e. arg_name: value, instead of filling preceding default arguments)

Attributes (instead of DocBlock comments)

Constructor property promotion (properties in constructor instead of normal declaration)

Union types (i.e. int|string $varname)

Match expression (to replace some of switch-case)

Nullsafe operator (instead of nesteds ifs)

Saner string to number comparisons (i.e. 0 == ‘somestrval’ // not true anymore)

Consistent type errors for internal functions (internal functions throws typed exceptions now)

Just-In-Time compilation (2x performance in some specific long-running applications)
and more

PHP 8.1 What’s new

Enumerations (enums)

Readonly Properties (for VO and DTO)

First-class Callable Syntax (to get a reference to any function, i.e. $fn = strlen(…);)

New in initializers (for nested attributes)

Pure Intersection Types (Iterator&Countable $value but not A&B|C)

Never return type (to be clear that function returns nothing)

Final class constants (cannot override functions and inherit classes)

Explicit Octal numeral notation // TODO: add some description below

Fibers
Array unpacking support for string-keyed arrays
and more

PHP 8.2 What’s new

Readonly classes
Disjunctive Normal Form (DNF) Types
Allow null, false, and true as stand-alone types
New “Random” extension
Constants in traits
Deprecate dynamic properties
and more

PHP 8.3. What’s new

Typed class constants
Dynamic class constant fetch
New #[Override] attribute
Deep-cloning of readonly properties
New json_validate() function
New Randomizer::getBytesFromString() method
New Randomizer::getFloat() and Randomizer::nextFloat() methods
Command line linter supports multiple files
and more