PHP Named Arguments

last modified February 15, 2025

In this article, we show how to use named arguments in PHP. Named arguments allow you to pass arguments to a function by specifying the parameter name, rather than relying on the order of the parameters. This feature was introduced in PHP 8.0 and provides more flexibility and readability when calling functions.

Main Features of PHP Named Arguments

Improved Readability: Named arguments make function calls more readable
by explicitly stating the purpose of each argument.
Flexibility: You can skip optional parameters without having to provide
default values for preceding parameters.
Order Independence: Named arguments allow you to pass arguments in any
order, as long as the parameter names are specified.
Reduced Errors: By using named arguments, you reduce the risk of passing
arguments in the wrong order.

Named arguments are particularly useful when dealing with functions that have many optional parameters or when the parameter order is not intuitive.

Basic Usage of Named Arguments

The following example demonstrates how to use named arguments in PHP.

main.php

<?php

declare(strict_types=1);

function createUser(string $name, int $age, string $email): void { echo “User created: $name, $age, $email\n”; }

createUser(name: “John Doe”, age: 30, email: “john@example.com”);

In this program, the createUser function is called using named arguments. The arguments are passed by specifying the parameter names, making the function call more readable.

$ php main.php User created: John Doe, 30, john@example.com

Skipping Optional Parameters

The following example demonstrates how to skip optional parameters using named arguments.

main.php

<?php

declare(strict_types=1);

function sendEmail(string $to, string $subject = “No Subject”, string $body = “”): void { echo “Sending email to: $to\n”; echo “Subject: $subject\n”; echo “Body: $body\n”; }

sendEmail(to: “john@example.com”, body: “Hello, John!”);

In this program, the sendEmail function is called with named arguments. The subject parameter is skipped, and the default value is used.

$ php main.php Sending email to: john@example.com Subject: No Subject Body: Hello, John!

Order Independence

The following example demonstrates how named arguments allow you to pass arguments in any order.

main.php

<?php

declare(strict_types=1);

function createProfile(string $name, int $age, string $country): void { echo “Profile created: $name, $age, $country\n”; }

createProfile(country: “USA”, name: “Jane Doe”, age: 25);

In this program, the createProfile function is called with named arguments in a different order than the parameter list. The function still works correctly because the arguments are identified by their names.

$ php main.php Profile created: Jane Doe, 25, USA

Combining Named and Positional Arguments

The following example demonstrates how to combine named and positional arguments in a function call.

main.php

<?php

declare(strict_types=1);

function createOrder(string $product, int $quantity, float $price): void { echo “Order created: $product, $quantity, $price\n”; }

createOrder(“Laptop”, price: 999.99, quantity: 1);

In this program, the createOrder function is called with a combination of positional and named arguments. The first argument is passed positionally, while the remaining arguments are passed by name.

$ php main.php Order created: Laptop, 1, 999.99

Using Named Arguments with Arrays

The following example demonstrates how to use named arguments with array parameters.

main.php

<?php

declare(strict_types=1);

function createPost(string $title, array $tags, string $content): void { echo “Post created: $title\n”; echo “Tags: " . implode(”, “, $tags) . “\n”; echo “Content: $content\n”; }

createPost(title: “PHP Named Arguments”, tags: [“PHP”, “Tutorial”], content: “Learn about named arguments in PHP.”);

In this program, the createPost function is called with named arguments, including an array parameter for tags.

$ php main.php Post created: PHP Named Arguments Tags: PHP, Tutorial Content: Learn about named arguments in PHP.

Named Arguments with Default Values

The following example demonstrates how to use named arguments with default values.

main.php

<?php

declare(strict_types=1);

function createEvent(string $name, string $date = “2025-01-01”, string $location = “Online”): void { echo “Event created: $name, $date, $location\n”; }

createEvent(name: “PHP Conference”, location: “New York”);

In this program, the createEvent function is called with named arguments, and the default value for the date parameter is used.

$ php main.php Event created: PHP Conference, 2025-01-01, New York

Named Arguments with Variadic Functions

The following example demonstrates how to use named arguments with variadic functions.

main.php

<?php

declare(strict_types=1);

function createReport(string $title, string …$sections): void { echo “Report created: $title\n”; echo “Sections: " . implode(”, “, $sections) . “\n”; }

createReport(title: “Annual Report”, “Introduction”, “Analysis”, “Conclusion”);

In this program, the createReport function is called with named arguments and variadic parameters for sections.

$ php main.php Report created: Annual Report Sections: Introduction, Analysis, Conclusion

Named Arguments with Object Parameters

The following example demonstrates how to use named arguments with object parameters.

main.php

<?php

declare(strict_types=1);

class User { public function __construct(public string $name, public int $age) {} }

function createUserProfile(User $user, string $bio): void { echo “User Profile: {$user->name}, {$user->age}\n”; echo “Bio: $bio\n”; }

createUserProfile(user: new User(name: “John Doe”, age: 30), bio: “Software Developer”);

In this program, the createUserProfile function is called with named arguments, including an object parameter for the user.

$ php main.php User Profile: John Doe, 30 Bio: Software Developer

Named Arguments with Callbacks

The following example demonstrates how to use named arguments with callback functions.

main.php

<?php

declare(strict_types=1);

function processData(array $data, callable $callback): void { $result = array_map($callback, $data); echo “Processed Data: " . implode(”, “, $result) . “\n”; }

processData(data: [1, 2, 3], callback: fn($n) => $n * 2);

In this program, the processData function is called with named arguments, including a callback function.

$ php main.php Processed Data: 2, 4, 6

Source

PHP Named Arguments - Documentation

In this article, we have shown how to use named arguments in PHP. Named arguments provide a flexible and readable way to pass arguments to functions, especially when dealing with functions that have many optional parameters.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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