PHP 8.2 includes a number of new features and improvements. Here are some of the main ones:
Improved Type Variance: PHP 8.2 introduces improved type variance for generic types, allowing you to specify whether a generic type is covariant, contravariant, or invariant. This can help to improve type safety and flexibility when working with generic types.
Performance Improvements: PHP 8.2 includes various performance improvements, including faster JIT compilation, faster garbage collection, and improved handling of large arrays. These improvements can help to make PHP applications faster and more efficient.
Deprecations: Some features have been deprecated in PHP 8.2, including the assert() function when used with a string argument, and the list() construct with a single array element. It's important to be aware of these deprecations if you are upgrading from an earlier version of PHP.
Here are some examples of features that have been deprecated in PHP 8.2:
assert() function with string argument: The assert() function can be used to perform runtime checks, but it has been deprecated when used with a string argument. Instead, you should use the assert() function with a boolean argument or an expression.
list() construct with a single array element: The list() construct allows you to unpack the elements of an array into separate variables. It has been deprecated when used with a single array element, as this usage was considered confusing and error-prone.
create_function(): The create_function() function has been deprecated, as it has been superseded by anonymous functions, which are more flexible and easier to use.
mb_ereg_replace_callback(): The mb_ereg_replace_callback() function has been deprecated, as it has been superseded by the preg_replace_callback() function, which provides similar functionality and is more widely used.
Callables that are not accepted by the $callable() syntax (but are accepted by call_user_func()) are deprecated.