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

#php

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.

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

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