Current Location: Home> Latest Articles> Detailed Explanation of PHP 7's use Keyword: Aliases, Dynamic and Static Calls

Detailed Explanation of PHP 7's use Keyword: Aliases, Dynamic and Static Calls

gitbox 2025-06-12

1. Introduction

PHP 7 is the latest version of the PHP language, officially released in December 2015. It brings significant improvements in performance, syntax, and features compared to previous versions. Among these changes, the use keyword in PHP 7 introduces some new functionalities, which will be explored in detail in this article.

2. Basic Usage of the use Keyword

In PHP, the use keyword is primarily used for importing namespaces or classes. The basic syntax is as follows:

<span class="fun">use Namespace\Class;</span>

You can also import multiple namespaces or classes:

use Namespace1\Class1;
use Namespace2\Class2;
use Namespace3\Class3;

By using the use keyword, you can reference the class without having to write the full namespace path every time. For example:

<span class="fun">$class1 = new Class1();</span>

3. Using the use Keyword for Aliases

In real-world development, you might often encounter situations where importing the same class or namespace results in a name conflict. In such cases, you can use the use keyword to create an alias for one of the classes or namespaces. For example:

<span class="fun">use Namespace\Class as MyClass;</span>

Then, you can use the alias name when referencing the class:

<span class="fun">$class1 = new MyClass();</span>

4. Using the use Keyword for Dynamic Class Calls

In PHP 5.x, to dynamically call a class at runtime, you had to use a string formatted class name. For example:

$className = 'Namespace\Class';
$class = new $className();

In PHP 7, the use keyword allows you to dynamically call classes even without knowing the class name in advance. For example:

use Namespace\{Class1, Class2, Class3};
$className = Class1::class;
$class = new $className();

Here, Class1::class returns the fully qualified class name, and you can dynamically create an instance.

5. Using the use Keyword for Static Class Calls

In PHP 5.x, when statically accessing a constant, property, or method of a class, you had to use the full class name. For example:

Namespace\Class::CONSTANT;
Namespace\Class::$property;
Namespace\Class::method();

In PHP 7, you can use the use keyword to access constants, properties, and methods statically without writing the full class name. For example:

use Namespace\Class;
echo Class::CONSTANT;
echo Class::$property;
echo Class::method();

6. Conclusion

Through this article, we've covered the new usages of the use keyword in PHP 7, including creating aliases, dynamic class calls, and static class calls. These new features help reduce code, improve development efficiency, and make the code more clear and maintainable.

Related