PHP 8 introduces JIT compilation, which improves the performance of PHP by compiling code into machine code at runtime.
This feature can offer significant performance improvements, particularly for CPU-bound tasks, though the benefits for typical web applications may be less noticeable.
2. Union Types
PHP 8 adds support for union types, which allow a function or method parameter to accept multiple types.
This provides greater flexibility for type declarations.
3.Named Arguments
PHP 8 introduces named arguments, allowing you to pass arguments to a function by specifying the parameter name, instead of relying on the order.
This makes the code more readable and allows for skipping optional parameters.
4. Attributes (Annotations)
PHP 8 introduces attributes, which provide a native way to add metadata to classes, methods, and properties. This replaces the need for docblock-based annotations.
Attributes can be used for things like routing, dependency injection, and validation in frameworks.
5. Constructor Property Promotion
This feature allows class properties to be promoted directly in the constructor signature, reducing boilerplate code.
This eliminates the need for separate property declarations and constructor assignments.
6. Match Expressions
PHP 8 introduces the match expression, which is similar to switch but with several improvements:
Strict comparison (===), no type coercion.
Can return values directly.
Supports multiple conditions in a single match arm.
7. Nullsafe Operator (?->)
The nullsafe operator (?->) allows you to call methods or access properties on objects that might be null without causing an error.
This eliminates the need for multiple null checks and makes the code cleaner.
8. Type System Improvements
PHP 8 introduces several changes to the type system:
Static return type: The static return type is now supported for fluent interfaces and methods that return an instance of the class itself.
Mixed type: The mixed type was added to explicitly indicate a value can be any type (previously, mixed was more of a concept rather than a declared type).
Improved type checking: Better handling of internal functions' types and improved consistency in error messages.
9. Error Handling Changes
PHP 8 changes the way some errors are handled:
Deprecation warnings: PHP 8 introduces new deprecations for features that will eventually be removed in future versions (e.g., #utf8_encode() and utf8_decode()).
TypeError and ValueError: Many cases that previously resulted in warnings now throw exceptions (such as passing an invalid argument type to a function).
10. Deprecations and Removed Features
Some features are deprecated or removed in PHP 8:
The real type: The real type has been removed in favor of float.
The each() function: The each() function is deprecated and removed in favor of using foreach.
The assert() function: The behavior of assert() is now more consistent with the AssertionError class.
11. Improvements to str_contains(), str_starts_with(), str_ends_with()
PHP 8 adds new helper functions to check if a string contains a substring, starts with a substring, or ends with a substring.
12. Other Miscellaneous Changes
Saner var_dump output: The output of var_dump() now includes more informative details.
Improvements to the filter_var() function: It includes better validation and sanitization features for URL filtering.
New str_split() behavior: The str_split() function now correctly handles multibyte characters.
