PHP8.0 new features: attribute improvement

At the end of 2020, the PHP community released the latest version of PHP8.0, which contains many new features and improvements. One of the most notable features is Property Promotion, a feature that simplifies writing code. In this article, we’ll take a closer look at attribute boosting and understand its benefits.

What is attribute improvement?

Attribute hoisting is a new programming syntax that simplifies the definition of class attributes by adding access control modifiers to class attribute declarations. Prior to PHP 8.0, each property needed to be defined at the top of the class and had to include its visibility and default value. This often leads to some duplication of code, especially if there are many attributes in the class.

In property hoisting, you can declare a class property while specifying its default value and specifying its visibility. This process usually follows the following syntax:

class Car {
   // PHP 8.0 and above
   public function __construct(
      private string $model,
      private string $year,
      private string $brand = 'Toyota'
   ){}
   // earlier versions of PHP
   public function __construct(
      string $model,
      string $year,
      string $brand = 'Toyota'
   ){
      $this->model = $model;
      $this->year = $year;
      $this->brand = $brand;
   }
}

In the above code, we have defined a Car class and specified three properties of the class through the constructor - $model, $year and $brand. We've used a new syntax to simplify property declarations, which makes the code easier to write and read. Depending on the actual needs of the class, the $brand attribute can optionally be set to a default value of 'Toyota'.

Before property promotion, using a more traditional syntax expression would be like this:

class Car {
   //PHP 7 and earlier
   public $model;
   public $year;
   public $brand;
   public function __construct(string $model, string $year, string $brand='Toyota'){
      $this->model = $model;
      $this->year = $year;
      $this->brand = $brand;
   }
}

In this example, we have added a little extra code. We first declare all the properties of the class using the public keyword, and then set their values ​​to the values ​​passed in the parameters or the default values ​​in the constructor. In this simple example, the benefits of property hoisting may not seem obvious, but this concise syntax can become particularly useful when working with more complex classes.

Benefits of property hoisting

1. Reduce the amount of manually entered code

Property hoisting eliminates the work of manually entering class properties, which makes the entire code base More readable. In earlier versions of PHP, setting all properties at the top of the class declaration was gradually extended and maintained, as this section tended to grow as the class was used. Now, it eliminates the need to write code again and again, allowing us to focus on the more important parts of the class.

2. Better code readability and maintainability

In the case of property promotion, the type and default value of each property are displayed in one place. This brings huge improvements to code readability and maintainability. Sometimes the value of an attribute may need to have different effects on different occasions. In this case, using attribute promotion can make the code more concise and readable.

3. Accelerate development

Property hoisting allows PHP developers to write code faster and reduces the repetitive work of defining all properties in a class. This is very important when working with large amounts of code, freeing up time to work on more important tasks.

Conclusion

Attribute promotion is an important change introduced in PHP 8.0. This is a very convenient and simplified feature for developers who need to define a large number of classes. We take a deeper look at the usage and benefits of attribute boosting in this article. When starting to use property hoisting, we need a right code management tool or IDE that can help automatically.

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