What are the main differences between PHP 7 and PHP 8?

Main differences between PHP 7 and PHP 8:

• JIT compilation: PHP 8 introduces a Just-In-Time compiler, which can improve the performance of certain computational tasks.

• New syntactic features:

  • Union Types, for example: function foo(int|float $number) {}
  • Named Arguments allow passing parameters by name.
  • Attributes (annotations) — a new way to add metadata to classes and methods.
  • Match expression — a more powerful alternative to switch.

• Changes in types and errors:

  • Stricter type and error handling.
  • New types, such as mixed.

• Removal of deprecated functions and improvements to the standard library.

Example of union types in PHP 8:

function foo(int|float $number) {
    return $number * 2;
}

PHP 8 significantly expands the language's capabilities and improves performance compared to PHP 7.