The latest version of PHP, PHP 8.1, was released on November 25, 2021. PHP 8.1 enhances error reporting by introducing more accurate messages and better context for debugging, leading to smoother development workflows.These enhancements make PHP 8.1 a compelling choice for building modern, robust web applications. In this overview, we’ll explore the new features, performance enhancements, changes, and deprecated elements introduced in PHP 8.1 , one by one.
1) ENUMS
Enums, short for enumerations, are a new feature introduced in PHP 8.1. Enums provide a way to define a set of named constants that represent a fixed list of possible values. They are particularly useful for improving code readability, type safety, and maintainability.
To give you a quick preview of what they will look like, here’s a code sample:
<?php
enum Status {
case Pending;
case Approved;
case Rejected;
}
function processStatus(Status $status): void {
match ($status) {
Status::Pending => echo "Status is Pending\n",
Status::Approved => echo "Status is Approved\n",
Status::Rejected => echo "Status is Rejected\n",
};
}
$status1 = Status::Pending;
$status2 = Status::Approved;
$status3 = Status::Rejected;
processStatus($status1);
processStatus($status2);
processStatus($status3);
?>
OUTPUT:
Status is Pending
Status is Approved
Status is Rejected
2) FIBERS
In PHP 8.1, fibers were introduced as a new feature to support asynchronous programming. Fibers provide a way to write asynchronous code in a synchronous style, improving concurrency and performance in PHP applications.
Let’s look at a simple code example to understand fibers:
<?php
$fiber = new Fiber(function () {
echo "Start fiber\n";
Fiber::yield(); // Yield to the main program
echo "Resume fiber\n";
});
echo "Main program\n";
$fiber->start(); // Start the fiber
echo "After starting fiber\n";
$fiber->resume(); // Resume the fiber
echo "End of program\n";
?>
OUTPUT:
Main program
Start fiber
After starting fiber
Resume fiber
End of program
3) INTERSECTION TYPES
PHP 8.1 introduces support for intersection types, a concept that differs significantly from union types introduced in PHP 8.0. While union types allow a value to meet any of the declared types, intersection types mandate that a value must satisfy all specified types simultaneously. This distinction is crucial in understanding how intersection types enhance type safety and provide more precise type annotations in PHP code. Intersection types are generally useful when you’re working with lots of interfaces.
To declare a intersection type in PHP 8.1, use & (AND) operator. Here’s an example:
<?php
class Animal {
public function eat(): void {
echo "Animal is eating\n";
}
}
interface Flyable {
public function fly(): void;
}
class Bird extends Animal implements Flyable {
public function fly(): void {
echo "Bird is flying\n";
}
}
function processBird(Bird&Animal&Flyable $bird): void {
$bird->eat();
$bird->fly();
}
$bird = new Bird();
processBird($bird); // This works since Bird is both an Animal and Flyable
?>
OUTPUT:
Animal is eating
Bird is flying
4) NEVER RETURN TYPE
The “never” return type was introduced in PHP 8.1 as a new return type that indicates a function or method will never return a value or will always throw an exception. This return type is primarily used for functions that exit the script execution or throw exceptions without returning a value.
Here’s a simple example using the “never” return type
<?php
function throwError(): never {
throw new Exception("This function always throws an exception.");
}
try {
throwError();
} catch (Exception $e) {
echo "Caught exception: " . $e->getMessage() . "\n";
}
?>
OUTPUT
Caught exception: This function always throws an exception.
5)READONLY PROPERTIES
In PHP 8.1, the readonly keyword was introduced to allow developers to declare class properties as read-only. Once a property is marked as readonly, it cannot be modified outside of the class constructor or initialization.
Here’s an example of how readonly properties work in PHP 8.1:
<?php
class Person {
public readonly string $name;
public readonly int $age;
public function __construct(string $name, int $age) {
$this->name = $name;
$this->age = $age;
}
}
$person = new Person('John Doe', 30);
echo "Name: " . $person->name . "\n;
echo "Age: " . $person->age . "\n";
// Trying to modify readonly properties (will result in an error)
// $person->name = 'Jane Doe'; // Error: Cannot modify readonly property Person::$name
// $person->age = 25; // Error: Cannot modify readonly property Person::$age
?>
OUTPUT:
Name: John Doe
Age: 30
CONCLUSION
PHP 8.1 brings a range of exciting new features and enhancements to the table, empowering developers with more tools to write efficient, reliable, and maintainable code.
Overall, PHP 8.1 represents another significant step forward for the PHP language, equipping developers with powerful features and tools to build modern and robust applications. Embracing these new capabilities can lead to more efficient development workflows and ultimately, better software solutions.